- By Jamie Roberton: ITV News Washington Producer
A manhunt is continuing after a bomb attack injured 29 people in New York City.
The explosive device ripped through the city's popular Chelsea district at around 9pm on Saturday night, causing considerable damage to surrounding buildings and sending glass and shrapnel on to passers by.
An unexploded second device, a pressure cooker wired to a mobile phone, was found just a few blocks away from the scene of the first blast.
Investigators studying CCTV footage may have identified the same man at each location, law enforcement sources told NBC New York.
- CCTV footage shows the effect of the blast.
Tamerlan and Dzhokhar Tsarnaev used homemade pressure cooker devices in the Boston Marathon bombings in 2013, killing three people and injuring more than 250 more.
All those injured in the explosion were released from hospital on Sunday evening.
New York Governor Andrew Cuomo said a bomb exploding in New York "is obviously an act of terrorism" but said there was currently no evidence that an international terrorist group such as so-called Islamic State was responsible.
Bill de Blasio, the city's mayor, refused to speculate on a possible motive, saying only that it was an "intentional act" and that investigators - who included members of the FBI and a special anti-terrorism taskforce - were working tirelessly to find those responsible.
An extra 1,000 security personnel have been deployed to reassure New Yorkers, as well as the hundreds of foreign leaders and diplomats who are arriving for the opening of the United Nations general assembly on Monday.
Earlier in the day, a pipe bomb exploded on the route of a road race in New Jersey.
No injuries were reported and it is unclear if there was any link to the incidents in New York.
The blasts also came on the same day as IS said one of its "soldiers" was responsible for a stabbing rampage that wounded at least eight people at a shopping centre in Minnesota. The knifeman was shot dead by an off-duty policeman.
The incidents over the weekend threaten to place national security back at the centre of the presidential election campaign.
Donald Trump, the Republican nominee, said the bombing was a "terrible thing" and vowed to "get tough", while his democratic rival, Hillary Clinton, condemned the "apparent terrorist attacks" in Minnesota, New Jersey and New York.