Police are still searching for a motive behind the bomb blast that injured 29 people in New York.
All the wounded have now left hospital and the authorities are urging the public to come forward with any information they may have.
The blast shook the Chelsea neighbourhood of Manhattan on Saturday night.
Video said to show moment of explosion
New York mayor Bill de Blasio urged against speculation as to the cause of the bombing. Security in the city is being tightened.
The blast, described by one person as “deafening,” happened outside the Associated Blind Housing facility at 135 W. 23rd Street. It provides housing, training and other services for the blind.
Following Saturday evening’s blast, a second explosive device was discovered four blocks away.
The bomb – in pressure cooker with wires attached – was removed and is still being analyzed.
‘It blew the back window out’
Hundreds of people were seen fleeing down the street on a cool evening, as police cordoned off the area.
“It was really loud, it hurt my eardrums. My 10-year-old boy was sat in the back seat of the car, and the explosion blew the back window out,” said Tsi Tsi Mallett, who was in a vehicle driving along 23rd Street when the explosion happened. Her son was not injured.
The blast happened just hours after a pipe bomb went off in a rubbish bin in a town in New Jersey, along the route of a charity race which was due to get underway.
De Blasio said there was no evidence of a link with the earlier explosion.