New York Mayor Bill de Blasio has said an explosion that wounded four people in one of the city's busiest commuter hubs in midtown Manhattan was "an attempted terrorist attack".
- Bangladeshi Akayed Ullah is suspected of setting off a bomb at a Manhattan bus terminal.
- Four people were wounded, including a police officer and the suspect.
- Ullah has been in the US for seven years and lived in Brooklyn with his parents.
Surveillance cameras captured a Bangladeshi man with a homemade bomb strapped to his body walking casually through a crowded passageway at the Port Authority Bus Terminal near Times Square.
The crude pipe bomb suddenly went off at 7:20am local time, with a plume of white smoke clearing to show the man sprawled on the ground and commuters fleeing in terror.
Investigators said it was not clear if the bomb was set off intentionally or went off prematurely.
"Thank God the perpetrator did not achieve his ultimate goals," Mr de Blasio said.
The suspect, who was identified as 27-year-old Akayed Ullah, was being treated at a hospital for burns to his hands and abdomen. He is believed to have acted alone.
Three other people, including a police officer, suffered minor injuries.
Law enforcement officials said Ullah was inspired by the Islamic State group, but did not have any direct contact with the terror organisation.
Ullah is from the Bangladeshi city of Chittagong and is a US resident, the country's police chief said.
He had no criminal record there and last visited Bangladesh on September 8.
Ullah had a black cab and limousine driver's licence from 2012 to 2015, after which it expired, the New York Taxi and Limousine Commission said.
Authorities said the bomb was a low-tech explosive device attached to the man with Velcro and plastic ties. They were investigating how it was made.
New York state Governor Andrew Cuomo, speaking at a news conference near the site, described the device as "amateur level".
He later told the NY1 cable channel that the suspect went online to learn how to make a bomb.
Video posted on The New York Post showed smoke and a man lying down in the tunnel that connects the Times Square subway station to the bus station.
A photograph showed a man lying face down, with tattered clothes and burns on his exposed torso.
The bus terminal, which services around 220,000 passengers daily, was temporarily shut down and a large swath of midtown Manhattan was closed to traffic.
Subway trains were bypassing the nearby Times Square station, the city's busiest with over 200,000 commuters a day.
Commuters described scenes of panic as people rushed to leave the terminal.
"There was a stampede up the stairs to get out," Diego Fernandez, one of the commuters at Port Authority, said.
"Everybody was scared and running and shouting."
Alicja Wlodkowski, a Pennsylvania resident in New York for the day, was sitting in a restaurant in the bus terminal.
"Suddenly, I saw a group of people, like six people, running like nuts. A woman fell. No-one even went to stop and help her because the panic was so scary," she said.
Elrana Peralta, a customer service worker for Greyhound, said she works in the Port Authority terminal complex near where the blast occurred, but did not hear the explosion.
"All we could hear was the chaos," she said.
"We could hear people yelling, 'Get out! Get out! Get out!'"
New York City has reopened its subways amid heightened city-wide security.
Suspect lived in Brooklyn
Law enforcement officials said the suspect has been in the United States for seven years and lives in Brooklyn.
Ullah lived with his father, mother and brother in a residential area of Brooklyn with a large Bangladeshi community, according to neighbours.
Police shut down the entire block around his home and there was a heavy police presence outside as they searched the property.
White House press secretary Sarah Huckabee Sanders tweeted that President Donald Trump had been briefed on the explosion.
Instead of commenting on the suspected terror attack, Mr Trump sent a tweet at 9:17am criticising a Sunday story in The New York Times that said he watched cable news television for at least four hours a day.
News of the incident jarred financial markets as trading was getting underway for the week.
The incident 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 group claimed responsibility.
In September 2016, a man injured more than two dozen people when he set off a homemade bomb in New York's Chelsea district.