U.S. investigators search for links in trio of weekend attacks

Before you go, we thought you'd like these...

NEW YORK/WASHINGTON, Sept 18 (Reuters) - Federal investigators sought to determine on Sunday if there were links among three attacks across the United States this weekend, involving bombings in New York City and New Jersey and a stabbing rampage at a Minnesota shopping mall.

While officials described all three as deliberate, criminal acts and are investigating them as potential "acts of terrorism," they stopped short of characterizing the motivation behind any of them until more evidence is uncovered.

SEE ALSO: Gasoline prices spike as Colonial begins bypass around damaged line

Twenty-nine people were wounded by an explosive device that rocked New York's Chelsea neighborhood late on Saturday, sending a deafening roar and powerful shock wave through several blocks of the popular Manhattan shopping district. Also on Saturday, nine people were stabbed in St. Cloud, Minnesota, 1,300 miles (2,100 km) away.

No international militant group immediately claimed responsibility for the New York blast, or for an undetonated pressure-cooker bomb found four blocks away or a similar device that went off earlier along the route of a Saturday road race in suburban New Jersey. But New York Governor Andrew Cuomo said the act of blowing up a bomb in a crowded area of Manhattan "is obviously an act of terrorism."

RELATED: See photos from the scene in New York

25 PHOTOS
Explosion in Manhattan and investigation
See Gallery
Explosion in Manhattan and investigation
Fire fighters and other first responders stand near an alleged explosion on West 23rd Street on September 17, 2016, in New York. An explosion in New York's upscale and bustling Chelsea neighborhood injured at least 25 people, none of them in a life-threatening condition, late Saturday, the fire department said. / AFP / Bryan R. Smith (Photo credit should read BRYAN R. SMITH/AFP/Getty Images)
Members of the NYPD, FBI, ATF and other agencies invesitgate the the scene, following a late night explosion on West 23rd Street September, 18, 2016 in New York. An explosion rocked one of the most fashionable neighborhoods of New York on September 17 night, injuring 29 people, one seriously, a week after America's financial capital marked the 15th anniversary of the 9/11 attacks. Mayor Bill de Blasio indicated the blast was not accidental, even if there was no known link to terrorism. The blast occurred in Chelsea -- an area packed with bars, restaurants and luxury apartment blocks -- at a typically bustling time of the weekend. / AFP / Bryan R. Smith (Photo credit should read BRYAN R. SMITH/AFP/Getty Images)
Members of the NYPD, FBI, ATF and other agencies invesitgate the the scene, following a late night explosion on West 23rd Street September, 18, 2016 in New York. An explosion rocked one of the most fashionable neighborhoods of New York on September 17 night, injuring 29 people, one seriously, a week after America's financial capital marked the 15th anniversary of the 9/11 attacks. Mayor Bill de Blasio indicated the blast was not accidental, even if there was no known link to terrorism. The blast occurred in Chelsea -- an area packed with bars, restaurants and luxury apartment blocks -- at a typically bustling time of the weekend. / AFP / Bryan R. Smith (Photo credit should read BRYAN R. SMITH/AFP/Getty Images)
Evidence markers are seen on the street around officials from the New York City Police Department (NYPD) and Federal Bureau of Investigation (FBI) near the site of an explosion in the Chelsea neighborhood of Manhattan, New York, U.S. September 18, 2016. REUTERS/Rashid Umar Abbasi TPX IMAGES OF THE DAY
New York Governor Andrew Cuomo(R)visits the scene of an explosion on West 23rd Street September, 18, 2016 in New York. An explosion rocked one of the most fashionable neighborhoods of New York on September 17 night, injuring 29 people, one seriously, a week after America's financial capital marked the 15th anniversary of the 9/11 attacks. Mayor Bill de Blasio indicated the blast was not accidental, even if there was no known link to terrorism. The blast occurred in Chelsea -- an area packed with bars, restaurants and luxury apartment blocks -- at a typically bustling time of the weekend. / AFP / Bryan R. Smith (Photo credit should read BRYAN R. SMITH/AFP/Getty Images)
The Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) officers stand near the site of an explosion in the Chelsea neighborhood of Manhattan, New York, U.S. September 18, 2016. REUTERS/Stephanie Keith
Police block a road after an explosion in New York on September 17, 2016. An explosion in New York's Chelsea neighborhood injured multiple people Saturday night, police said. / AFP / William EDWARDS (Photo credit should read WILLIAM EDWARDS/AFP/Getty Images)
Explosion on 23rd and 6th. These two cars had back windows blown out while driving. 8 year old in back seat injured. https://t.co/aKDra2LaIC
Apartment is being blocked off - #Explosion #Chelsea #NewYork https://t.co/B14pWOFpZ0
#Explosion outside our apartment at 23rd and 6th in #newyork. Terrified. Hoping everyone is okay. https://t.co/i3q4cG7aWT
23rd and 6th Ave NYC explosion. Emergency responded within seconds https://t.co/3ZOYQJ2A5J
The situation at 23rd and 6th in NYC. Explosion happened on 23rd, subway station blocked off. https://t.co/NPNjXqIerH
Bomb squad just arrived... Block has been cordoned off between 6th and 7th on 23rd st. https://t.co/vnZ4TxciGj
Two woman look on as police block a road after an explosion in New York on September 17, 2016. An explosion in New York's Chelsea neighborhood injured multiple people Saturday night, police said. / AFP / William EDWARDS (Photo credit should read WILLIAM EDWARDS/AFP/Getty Images)
New York City firefighters stand near the site of an explosion in the Chelsea neighborhood of Manhattan, New York, U.S. September 17, 2016. REUTERS/Rashid Umar Abbasi
New York City firefighters stand near the site of an explosion in the Chelsea neighborhood of Manhattan, New York September 17, 2016. REUTERS/Rashid Umar Abbasi TPX IMAGES OF THE DAY
New York City police and firefighters stand near the site of an explosion in the Chelsea neighborhood of Manhattan, New York, U.S. September 17, 2016. REUTERS/Rashid Umar Abbasi
People look on as the police, fire department and other first responders work near an alleged explosion on West 23rd Street on September 17, 2016, in New York. An explosion in New York's upscale and bustling Chelsea neighborhood injured at least 25 people, none of them in a life-threatening condition, late Saturday, the fire department said. / AFP / Bryan R. Smith (Photo credit should read BRYAN R. SMITH/AFP/Getty Images)
Democratic nominee Hillary Clinton talks to reporters about the explosion in Chelsea neighborhood of Manhattan, New York, as she arrives to at the Westchester County airport in White Plains, U.S., September 17, 2016. REUTERS/Carlos Barria
NEW YORK, NY - SEPTEMBER 18: Security members take security measures at Grand Central Station after the explosion in Chelsea neighbourhood in Manhattan, New York, USA on September 18, 2016. (Photo by Bilgin S. Sasmaz/Anadolu Agency/Getty Images)
NEW YORK, NY - SEPTEMBER 18: Security members take security measures at site after the explosion in Chelsea neighbourhood in Manhattan, New York, USA on September 18, 2016. (Photo by Bilgin S. Sasmaz/Anadolu Agency/Getty Images)
Members of the NYPD, FBI, ATF and other agencies invesitgate the the scene, following a late night explosion on West 23rd Street September, 18, 2016 in New York. An explosion rocked one of the most fashionable neighborhoods of New York on September 17 night, injuring 29 people, one seriously, a week after America's financial capital marked the 15th anniversary of the 9/11 attacks. Mayor Bill de Blasio indicated the blast was not accidental, even if there was no known link to terrorism. The blast occurred in Chelsea -- an area packed with bars, restaurants and luxury apartment blocks -- at a typically bustling time of the weekend. / AFP / Bryan R. Smith (Photo credit should read BRYAN R. SMITH/AFP/Getty Images)
NEW YORK, NY - SEPTEMBER 18: A mangled dumpster sits on the sidewalk at the site of an explosion that occurred on Saturday night on September 18, 2016 in the Chelsea neighborhood of New York City. An explosion in a construction dumpster that injured 29 people is being labeled an 'intentional act'. A second device, a pressure cooker, was found four blocks away that an early investigation found was likely also a bomb. (Photo by Justin Lane-Pool/Getty Images)
NEW YORK, NY - SEPTEMBER 18: New York Governor Andrew Cuomo (R) and New York Mayor Bill de Blasio (L) talk to area residents while touring the site of an explosion that occurred on Saturday night on September 18, 2016 in the Chelsea neighborhood of New York City. An explosion in a construction dumpster that injured 29 people is being labeled an 'intentional act'. A second device, a pressure cooker, was found four blocks away that an early investigation found was likely also a bomb. (Photo by Justin Lane-Pool/Getty Images)
of
SEE ALL
BACK TO SLIDE
SHOW CAPTION +
HIDE CAPTION

No suspects were immediately identified in the New York and New Jersey attacks.

The Islamic State militant group quickly claimed responsibility for the Minnesota attack by a man who made references to Allah and asked at least one person if he or she was Muslim before he assaulted the person. An off-duty police officer fatally shot the assailant.

Police did not immediately identify the Minnesota attacker, citing an ongoing investigation, although some local media reports gave his name and said he was an African-born junior college student. Reuters could not immediately confirm his identity.

ADDITIONAL POLICE DEPLOYED

In New York, officials said they would deploy an additional 1,000 uniformed police officers and National Guard troops around a city already on a high state of alert heading into this week's United Nations General Assembly. The event will bring some 135 heads of state and government to America's most populous city.

Federal Bureau of Investigation experts were examining remnants of the two devices that went off in Chelsea and Seaside Park, New Jersey, some 80 miles (130 km) south of New York City, as well as the third undetonated device. That third device was built in a pressure cooker, the same bomb design that killed three people and wounded more than 260 in the 2013 Boston Marathon bombing.

A law enforcement official who spoke on condition of anonymity said investigators considered it very strange that similar devices would be planted adjoining states on the same day.

No one was hurt by the New Jersey pipe bomb.

Both presidential candidates spoke out about the attacks, with Democrat Hillary Clinton on Sunday issuing a statement condemning "the apparent terrorist attacks." On Saturday, Republican Donald Trump said following the New York blast: "We better get very tough, folks."

The United States has experienced a series of deadly attacks over the past year by gunmen inspired by Islamic State, which has been fighting a long civil war in Syria. A man who claimed allegiance to the group fatally shot 50 people at an Orlando, Florida, nightclub in June, six months after a married couple massacred 14 in San Bernardino, California.

All of the New York victims had been released from the hospital by Sunday, Mayor Bill de Blasio said. Three of the people wounded in Minnesota remained in the hospital on Sunday, although their injuries were not considered life-threatening, St. Cloud Mayor Dave Kleis told a news conference.

RELATED: See images from the scene in New Jersey

8 PHOTOS
Pipe bomb explodes near NJ race
See Gallery
Pipe bomb explodes near NJ race
Very loud explosion at Semper 5K in Seaside Park at E Street. OMG #explosion #seasidepark https://t.co/4K5V7gXpy8
Seaside Park Police at the scene. #seasidepark'sfinest https://t.co/Ci8chr9YZp
Look at black can. Hole in side. Explosion 9:30ish. There is also a backpack Seaside Park police are checking out https://t.co/JtEXuVZM7J
Possible Pipe Bomb Explodes in Garbage Can near Jersey Shore Boardwalk: https://t.co/Q7X5Y2JCFd https://t.co/euJqehfmha
Pipe bomb explodes at NJ Marines charity run https://t.co/TPfmxIXakE https://t.co/qXXMRTwBTd
Pipe bomb explodes ahead of Marines charity run in New Jersey https://t.co/AcsscOQq80 https://t.co/qcYmZorjSY
🆘‼️🔥 USA: During a military charity race a pipe bomb exploded in a trash can at the #seasidepark (NJ) near #Trenton. https://t.co/kdSrfDShIa
of
SEE ALL
BACK TO SLIDE
SHOW CAPTION +
HIDE CAPTION

'ALL OVER THE INTERNET'

Investigators at the FBI's lab in Quantico, Virginia, were set to look to see if the three devices in the New York area had a common design, although a U.S. official familiar with the inquiry said that would not be proof in itself the attacks were linked.

"Almost anybody could have fabricated these bombs and used cellphones as timed detonators," said the official. "There are instructions all over the internet, and the crudity, positioning, and relative ineffectiveness of these does not suggest that a more sophisticated group played any role in this."

The bombs used in the Boston Marathon bombing were built using instructions that the pair of brothers behind the attack found on al Qaeda's "Inspire" online magazine.

RELATED: Terrorism casualties in the United States by attack tactic

The FBI considers the Minnesota episode a "potential act of terrorism," Richard Thornton, FBI special agent in charge of the agency's Minneapolis division, told a news conference on Sunday.

He said the investigation was in its early stages and it was not known if the man had discussed his plan of attack with others.

Amaq, the news agency affiliated with Islamic State, issued a statement on Sunday saying: "The executor of the stabbing attacks in Minnesota yesterday was a soldier of the Islamic State and carried out the operation in response to calls to target the citizens of countries belonging to the crusader coalition."

Reuters was not immediately able to verify the Amaq assertion. (Additional reporting by Mark Hosenball in Washington, Robert MacMillian in New York and Alex Dobuzinskis in Los Angeles; Writing by Scott Malone; Editing by Peter Cooney)

Read Full Story

People are Reading