At least 29 people injured in explosion that shakes New York City

An explosion rocked the Chelsea neighborhood of Manhattan on Saturday night, injuring at least 29 people, authorities said, adding that they are investigating the blast as a criminal act not immediately linked to any terror organization.

Mayor Bill de Blasio said early indications were that blast was intentional. He said the site of the explosion, outside on a major thoroughfare of a fashionable enclave in one of the most bustling areas of New York City, was being treated as a crime scene.

But he said there was no evidence of a "credible and specific threat" to the city. "We do not see a link to terrorism," he added.

"It is too early to determine what the incident was caused by. We believe it was intentional. A full investigation is under way."

See images from the scene:

A U.S. official said that Joint Terrorism Task Force, an interagency group of federal, state and local officials, was called to investigate the Chelsea blast, suggesting authorities have not ruled out the possibility of a terror connection.One report on Twitter claimed the "huge explosion" blew out a dumpster.

Police combing the area around the scene of an explosion on Saturday in Manhattan's Chelsea neighborhood found a pressure cooker nearby connected to a cell phone with wires attached, CNN reported, citing law enforcement sources.

One witness told the New York Daily News that he saw the back of an SUV "totally blown out" after hearing the explosion while entering the subway.

"Everybody started running and screaming," the witness said.

Another witness said he saw at least one person injured on the scene.

Earlier on Saturday, a pipe bomb exploded near the route of a 5K race charity race in the beach town of Seaside Heights, New Jersey. No one was injured, but federal authorities are investigating the incident as possible terrorism.

It was unclear initially if anyone had been injured in the Manhattan explosion.

This is a developing story. Please return to AOL for updates.

(Reporting by AOL.com; Additional reporting by Reuters)