WASHINGTON, April 13 (Reuters) - The United States dropped a massive GBU-43 bomb, the largest non-nuclear bomb it has ever used in combat, in eastern Afghanistan on Thursday against a series of caves used by Islamic State militants, the military said.
It was the first time the United States has used this size of bomb in a conflict. It was dropped from a MC-130 aircraft in the Achin district of Nangarhar province, close to the border with Pakistan, Pentagon spokesman Adam Stump said.
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A billboard (L) with Koranic verses is seen in the historic city of Palmyra, in Homs Governorate, Syria April 1, 2016. REUTERS/Omar Sanadiki SEARCH "PALMYRA SANADIKI" FOR THIS STORY. SEARCH "THE WIDER IMAGE" FOR ALL STORIES
An Islamic State flag hangs on the wall of an abandoned building in Tel Hamis in Hasaka countryside after the Kurdish People's Protection Units (YPG) took control of the area March 1, 2015. Kurdish forces dealt a blow to Islamic State by capturing Tel Hamis, an important town, on Friday in the latest stage of a powerful offensive in northeast Syria, a Kurdish militia spokesman said. The capture of Tel Hamis was announced by the Kurdish YPG militia and confirmed by the Syrian Observatory for Human Rights, which monitors the country's civil war. REUTERS/Rodi Said (SYRIA - Tags: POLITICS CIVIL UNREST CONFLICT)
Tripods and a projector are pictured inside an ancient Hammam that was used by Islamic State militants as a media centre in Manbij, in Aleppo Governorate, Syria, August 16, 2016. REUTERS/Rodi Said
A view shows part of a media centre that belonged to Islamic State militants inside an ancient Hammam in Manbij, Aleppo Governorate, Syria, August 16, 2016. REUTERS/Rodi Said
A tunnel used by Islamic State militants is seen in the town of Sinjar, Iraq December 1, 2015. REUTERS/Ari Jalal
A view shows car parts, which according to Syria Democratic Forces (SDF) fighters were used by Islamic State militants to prepare car bombs, at a workshop in Manbij, Aleppo Governorate, Syria, August 17, 2016. REUTERS/Rodi Said
Iraqi soldiers inspect a vehicle used for suicide car bombings, made by Islamic State militants, in Mosul, Iraq, January 25, 2017. REUTERS/Muhammad Hamed
A captured Islamic State tank and shells are seen at the Iraqi army base in Qaraqosh, east of Mosul, Iraq November 8, 2016. REUTERS/Zohra Bensemra TPX IMAGES OF THE DAY
Rocket-propelled grenades left behind by Islamic State militants are seen at a school, following clashes in Falluja, Iraq, June 25, 2016. REUTERS/Thaier Al-Sudani
Explosives left behind by Islamic State militants are seen at a school, following clashes in Falluja, Iraq, June 25, 2016. REUTERS/Thaier Al-Sudani
A member of Iraqi security forces takes a selfie at a building that was used by Islamic State militants in Hammam al-Ali, south of Mosul, Iraq November 7, 2016. REUTERS/Thaier Al-Sudani
A book belonging to Islamic State militants is seen in Falluja after government forces recaptured the city from Islamic State militants, Iraq, June 27, 2016. REUTERS/Thaier Al-Sudani
An Iraqi officer displays Russian passports, which he says belong to Islamic State fighters, in Mosul, Iraq, January 25, 2017. REUTERS/Muhammad Hamed
A man who fled the Islamic State stronghold of Mosul shows his marriage certificate issued by the Islamic State militants at temporary court at Khazer camp in Iraq, January 18, 2017. Picture taken January 18, 2017. REUTERS/Ahmed Saad
A member of the Iraqi counterterrorism forces stands by an Islamic State militants weapons factory in Falluja, Iraq, June 23, 2016. REUTERS/Thaier Al-Sudani TPX IMAGES OF THE DAY
A Syria Democratic Forces (SDF) fighter inspects a room, which according to the SDF was used by Islamic State militants to prepare explosives, in Manbij, Aleppo Governorate, Syria, August 17, 2016. REUTERS/Rodi Said
U.S. Special Operations Forces members inspect a drone used by Islamic State militants to drop explosives on Iraqi forces, in Mosul, Iraq, January 25, 2017. REUTERS/Muhammad Hamed
A member of Iraqi security forces inspects a building that was used as a prison by Islamic State militants in Hammam al-Ali, south of Mosul, during an operation to attack Islamic State militants in Mosul, Iraq November 7, 2016. REUTERS/Thaier Al-Sudani
A mass grave for Islamic State militants are seen in Falluja, Iraq, September 4, 2016. REUTERS/Khalid al Mousily
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Also known as the "mother of all bombs," the GBU-43 is a 21,600 pound (9,797 kg) GPS-guided munition and was first tested in March 2003, just days before the start of the Iraq war.
The security situation in Afghanistan remains precarious, with a number of militant groups trying to claim territory more than 15 years after the U.S. invasion which toppled the Taliban government.
BREAKING: US drops GBU-43/B, largest non-nuclear bomb in Afghanistan in anti-ISIS operation. First for battlefield. (via @barbarastarrcnn)
General John Nicholson, the head of U.S. and international forces in Afghanistan, said thebomb was used against caves and bunkers housing fighters of the Islamic State in Afghanistan, also known as ISIS-K.
It was not immediately clear how much damage the device did.
White House spokesman Sean Spicer opened his daily news briefing speaking about the use of the bomb and said, "We targeted a system of tunnels and caves that ISIS fighters used to move around freely, making it easier for them to target U.S. military advisers and Afghan forces in the area."
ALP CD-R Achin tells me,big bomb was dropped against a series of tunnels in Asadkhel area NAchin district.At least 20 to30 fighters killed
Last week, a U.S. soldier was killed in the same district as the bomb was dropped while conducting operations against Islamic State.
"The United States takes the fight against ISIS very seriously and in order to defeat the group, we must deny them operational space, which we did," Spicer said.
He said the bomb was used at around 7 p.m. local time and described the device as "a large, powerful and accurately delivered weapon." The United States took "all precautions necessary to prevent civilian casualties and collateral damage," he said.
U.S. officials say intelligence suggests Islamic State is based overwhelmingly in Nangarhar and neighboring Kunar province.
Estimates of its strength in Afghanistan vary. U.S. officials have said they believe the movement has only 700 fighters but Afghan officials estimate it has about 1,500.
Islamic State's offshoot in Afghanistan is suspected of carrying out several attacks on minority Shi'ite Muslim targets.
The Afghan Taliban, which is trying to overthrow the U.S.-backed government in Kabul, are fiercely opposed to Islamic State and the two group have clashed as they seek to expand territory and influence. (Reporting by Idrees Ali and Will Dunham; Editing by Alistair Bell)