New York bomb suspect charged with terror offences

The suspect arrested after a bomb attack in New York on Monday has been charged with terror offences and possession of a weapon.

Akayed Ullah, from Bangladesh, has been charged with criminal possession of a weapon, supporting an act of terrorism and making a terroristic threat.

He will face further federal terrorism charges later over allegations he set off a pipe bomb in a city commuter hub.

New York governor Andrew Cuomo told CNN the "amateur-level" bomb may not have fully ignited, which limited the damage.

Ullah, 27, was injured, along with three other people who were taken to hospital with non-life threatening injuries.

The bomb blast occurred during the morning rush hour at around 7.30am in a busy passageway linking two subways beneath Manhattan's Port Authority terminal - the nation's largest bus hub.

Police believe the bomb went off prematurely between Seventh and Eighth Avenues on 42nd Street and could have been intended for a busier destination.

"Let's be clear, as New Yorkers, our lives revolve around the subways," New York Mayor Bill de Blasio told a news conference.

"And let's also be clear, this was an attempted terrorist attack."

Investigators in Bangladesh have been questioning Ullah's wife, according to officials, who did not provide details.

They said the couple have a six-month-old baby boy.

One of the police officials told Reuters: "We have found his wife and in-laws in Dhaka. We are interviewing them."

Ullah's cousin, Emdad Ullah, told Reuters that his family came from the Chittagong region in southern Bangladesh, but moved to the capital, Dhaka, years ago.

Ullah married a Bangladeshi woman from Dhaka about two years ago, the cousin said, adding that he was educated in Bangladesh before moving to the US.

Bangladesh's police chief said on Monday that Ullah had no criminal record in his home country, which he last visited in September.

Ullah lived with his mother, sister and two brothers in Brooklyn and was a green card holder, a Bangladeshi consular official said.

Police claimed Ullah had looked at Islamic State group propaganda online and told investigators he was retaliating over actions by the US military.

Authorities have appealed for information.

Donald Trump said the blast in Manhattan showed the need to tighten up the immigration system.