One New Yorker at the scene, John Frank, said that the blast was strong enough to be felt through the sidewalk.
Four people have been injured in a blast at a subway station in the heart of Manhattan, in what the mayor of NY said was an "attempted terrorist attack".
All four were sent to the hospital for treatment. "And let's also be clear, this was an attempted terrorist attack".
An explosion was reported in a subway passage at the Port Authority in New York City during Monday's morning commute. Many people were in the passageway when the explosion caused it to fill with smoke.
The incident has occurred less than two months after an Uzbek immigrant killed eight people by speeding a rental truck down a New York City bike path, in an attack for which Islamic State claimed responsibility.
The New York City Fire Department later tweeted, "Update: A total of 4 injuries reported at the scene of an explosion at Port Authority".
Sources say Ullah told investigators he was inspired to strike by the terror group ISIS, but authorities were working to determine whether he had any direct connection with the group.
"We have the best law enforcement on the globe and now are all working together extremely well", he said.
The tenants did not call police, he said. It shows the suspect on the ground and people fleeing the area.
"The choice of NY is always for a reason".
A senior emergency official told The New York Times that the suspect was seriously injured.
An explosion that reportedly went off around 7:30 a.m. this morning inside the Port Authority subway station prompted the NYPD to shut down the station along with the Times Square subway stop, which is connected to it by a tunnel.
In September, an attack on a London train injured 29 (paywall) when a bomb concealed in a bucket exploded during rush hour. She did not hear the explosion.
- Ullah was not licensed to drive a NYC yellow taxi, he said. Get out! Get out!'
John Miles, 28, from Vermont, was waiting for a bus to MA. He also did not hear the explosion, but saw police react.
"I was going through the turnstile", he said. Officers were running around. There was an announcement that people should take their bags and leave.
Following Monday's attack, commuters told of mass chaos and a "stampede" following the explosion as NY commuters fled in terror through the smoky passageway.
First reports of the incident began soon after 7 a.m. (1200 GMT), at the start of the city's rush hour.
Hai Do adapted this story for Learning English based on AP news reports.
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