A man with a bomb-like device strapped to his body set off an explosion at one of New York's busiest commuter hubs at rush hour, injuring himself and three others.
The suspect in the incident at the Port Authority Bus Terminal, a block from Times Square, was identified as Akayed Ullah, 27, the New York Police Department commissioner said. The suspect had burns and cuts while three other people, including a police officer, had minor injuries.
Police said the weapon was based on a pipe bomb and was fixed to the suspect with zip ties and velcro.
New York Governor Andrew Cuomo, speaking at a news conference near the site, described the device as "amateur level."
New York Mayor Bill de Blasio told the same news conference that the incident, which happened at the start of the city's rush hour, was "an attempted terrorist attack."
"Terrorists won't win," he said.
"As New Yorkers our lives revolve around the subways. When we hear of an attack in the subways it is incredibly unsettling."
Mr de Blasio said the suspect was believed to have acted alone.
The incident was captured on security video, the police said.
A photo circulating on social media shows a man, said to be the suspect, lying on the ground with his clothes ripped and lacerations on his upper body.
Mr Cuomo said: "This is New York. The reality is that we are a target by many who would like to make a statement against democracy, against freedom.
"We have the Statue of Liberty in our harbour and that makes us an international target."
The explosion occurred at about 7.30am. Andre Rodriguez, 62, told the New York Times: "I was going through the turnstile. It sounded like an explosion, and everybody started running."
Another eyewitness, Alicja Wlodkowski, told Reuters news agency that she had seen a group of about 60 people running. "A woman fell. And nobody even went to stop and help her because the panic was so scary," she said.
Nearby subway stations were evacuated, and the Port Authority Bus Terminal shut down.
It is the biggest and busiest bus terminal in the world, serving more than 65 million people a year.
- Reuters / BBC