The man accused of Monday's New York subway bombing has been charged with supporting an act of terrorism, the city's police department has said.

The New York Police Department said on Twitter that Akayed Ullah also has been charged with making a terrorist threat and weapon possession.

Federal charges are expected later.

Deputy Commissioner for Counterterrorism and Intelligence John Miller said on CBS This Morning that Ullah was not on police or the FBI's radar before the Monday morning bomb in Times Square.

Bomb-sniffing dogs were part of the police presence as commuters resume their daily activities in the wake of the blast in a subway passageway.

The passageway connecting the Port Authority bus terminal and the Times Square subway station was back in use one day after the bomb exploded there.

Maintenance worker Jorge Garcia, who was taking the train out of Times Square on Tuesday, says he has got used to security concerns.

He says he was about three blocks away when the World Trade Centre came down.

Mr Garcia says he tries not to think about "the negative stuff" so he can "have a positive day".

Ullah's family have said they are heartbroken and deeply saddened by the suffering the attack has caused.

In a statement Ullah's family also said they were outraged by the way it had been handled by law enforcement, which included pulling a teenage relative from class and questioning him without a parent, guardian or lawyer present.

The family said they expected more from the justice system in a statement released by Albert Fox Cahn, legal director for the Council on American-Islamic Relations in New York.

Ullah, an immigrant from Bangladesh, was the only person seriously injured in the blast during the Monday morning rush hour that sent commuters scurrying in panic.

In a statement the government of Bangladesh condemned the attack, saying: "Bangladesh is committed to its declared policy of 'zero tolerance' against terrorism, and condemns terrorism and violent extremism in all forms or manifestations anywhere in the world, including Monday morning's incident in New York City."

Police in Bangladesh said on Tuesday that they were not in a position to comment on the suspect.

US law enforcement officials earlier said the pipe bomb was ignited with a Christmas light, matches and a nine-volt battery.

The officials said the short pipe was packed with explosive powder, but did not work as intended and the blast was not powerful enough to turn the pipe into deadly shrapnel.

Law enforcement officials familiar with the investigation said Ullah had looked at Islamic State group propaganda online and told investigators he was retaliating against US military aggression.

The blast during the Monday morning rush hour injured three people besides Ullah, who was being treated at a hospital.

President Donald Trump said the blast in Manhattan highlighted the need for an immigration overhaul.

Mr Trump said the US "must fix its lax immigration system, which allows far too many dangerous, inadequately vetted people" into the country.

He pointed to his controversial travel ban as an example of the kind of policy that needs to be put in place.

He called on Congress to end "chain migration," in which family members are permitted to join relatives who have immigrated.

He also said people convicted of terror acts "deserve the strongest penalty allowed by law, including the death penalty in appropriate cases".