None of the injuries is life-threatening but one is serious, New York’s fire commissioner said.
The cause of the explosion is yet to be determined but Mayor Bill de Blasio described it as “intentional” but said that there were no known terror links.
A few hours later, the authorities found and removed what they described as a second explosive device four blocks away, raising the possibility that two bombs had been planted in the heart of the city.
An unnamed law enforcement official said the device at the second Chelsea location appeared to be a pressure cooker attached to wiring and a mobile phone.
In the aftermath, the police shut down a swath of Manhattan south of Midtown. The area from 14th Street to 32nd Street was closed to traffic between Fifth and Eighth Avenues until further notice.
The explosion York occurred around 21:00 (01:00 GMT on Sunday). Witnesses said people ran in all directions following the “incredibly loud” blast.
Unconfirmed reports said the blast went off in a dustbin, shattering windows in a nearby building. Several blocks have been closed down by police.
Mr de Blasio said: “We do not see a link to terrorism.” He said it was too early to determine the cause but added: “We believe it was intentional.”
He also said there was no evidence of a link to a pipe bomb explosion in neighbouring New Jersey hours earlier.
In Washington, the White House issued a brief statement saying that President Obama had been briefed on the developing situation in New York.
Both the Democratic and Republican presidential candidates broke from their campaign routines to address the issue.
Donald J. Trump, in Colorado Springs, rushed to describe the explosion as a bomb well before the authorities had made any determinations about what had happened and while the situation was still in flux.
“I must tell you that just before I got off the plane, a bomb went off in New York and nobody knows exactly what’s going on,” he said. “But boy, we are living in a time — we better get very tough, folks.”
The Democratic nominee, Hillary Clinton, was informed of the episode after she gave a speech at the Congressional Black Caucus Foundation’s annual awards dinner, her campaign said.
She seemed to scold Mr. Trump for his quick assessment.
“I think it’s always wiser to wait until you have information before making conclusions,” Mrs. Clinton said.
Officials said the New York explosion was not connected to a blast that happened 11 hours before when an improvised device exploded in a garbage can near the course of a charity race that was about to start in a small town on the Jersey Shore. That device went off around 9:30 a.m. near the boardwalk in Seaside Park, N.J., according to the Ocean County sheriff, Michael G. Mastronardy.
There were no injuries. The race, the Seaside Semper Five, a five-kilometer run and charity event along the waterfront that raises money for members of the United States Marine Corps and their families, was canceled.
BBC & New York Times
