An explosion struck the Port Authority bus terminal at 42nd Street and Eighth Avenue, on Monday morning, the New York Police Department said, in a tweet.
The station is one of the busiest commuter hubs during rush hour.
The A, C and E subway lines are being evacuated, NYPD Sgt. Brendan Ryan said.
One person is in custody, according to two NYPD sources with direct knowledge of the situation.
Preliminary information, according to two law enforcement sources, one local and one federal, indicates a pipe bomb may have unintentionally exploded. The person in custody appears to be injured, according to the federal law enforcement source.
Another New York police source says a man in custody may have set off a device, injuring himself.
Francisco Ramirez said he heard two explosions as he was exiting a bus about 7:45 a.m. ET. He heard both blasts distinctly even though he was wearing headphones.
“From what I saw it sounded like it came from the subway, but I’m just guessing,” he said. “It was two distinct explosions seconds from each other. As I was making my way toward the outside, I kept getting shoved by cops and there were cops at every entrance blocking and there was police and SWAT everywhere.
“It was scary. It was just a lot of chaos but I didn’t see any injuries.” (CNN)