The FBI has released details of a man they are hunting in connection with an explosion in Manhattan on Saturday and the discovery of other devices.
Ahmad Khan Rahami, 28, is originally from Afghanistan and is a naturalised American living in New Jersey.
"Rahami is wanted for questioning in connection with an explosion that occurred on September 17, 2016, at approximately 8:30 pm in the vicinity of 135 West 23rd Street, New York, New York," investigators said.
He is described as 5 ft 6in tall and weighing 200 pounds. He has brown hair and brown eyes.
Investigators believe they may be hunting a terrorist cell, just as world leaders arrive in New York for the United Nations General Assembly.
Some 29 people were wounded on Saturday night when an apparently home-made bomb exploded in a dumpster in the Chelsea neighbourhood
The jittery city was put further on edge when a second device - made from a pressure cooker - was found streets away.
Five more pipebombs were found early on Monday morning in New Jersey.
Bill de Blasio, the mayor of New York, said Rahami could be armed and dangerous.
"We need to get this guy in right away," he said on CNN. "My experience is one the FBI zeroes in on someone, they will get them."
Authorities are still working to determine whether there is a connection between multiple explosive devices found in Manhattan and at a railway station in Elizabeth, New Jersey.
On Sunday night, FBI agents in Brooklyn stopped what they descibed as "a vehicle of interest" in the investigation of the Manhattan explosion, according to FBI spokeswoman Kelly Langmesser.
She declined to provide further details, but a government official and a law enforcement official who were briefed on the investigation told The Associated Press that five people in the car were being questioned at an FBI building in Manhattan.
