US officials are looking for Ahmad Khan Rahami, a naturalised US citizen who was born in Afghanistan, for questioning over explosions in New York and New Jersey on Saturday.
The FBI warned that the suspect is “armed and dangerous”.
Further devices exploded in Elizabeth, New Jersey, in the early hours of Monday as a police robot investigated a bag. No-one was injured.
The FBI has been searching the 28-year-old suspect’s family home in Elizabeth.
The bomb that hit Manhattan’s Chelsea district on Saturday evening injured 29, and an unexploded device was found nearby.
Early on Saturday a pipe bomb exploded in a New Jersey shore town ahead of a charity race. No-one was hurt.
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Democratic presidential candidate Hillary Clinton has urged jittery Americans to be “vigilant but not afraid”.
“It is crucial that we continue to build up trust between law enforcement and Muslim American communities,” she said.
New York Governor Andrew Cuomo said there were “certain commonalities” between the bombs.
New Jersey State Police said that the FBI was linking the Manhattan explosion to that in Seaside Park, New Jersey.
Millions of New York residents received a phone alert on Monday morning after the Notify NYC alert system was used to name the suspect.
“Anyone who sees this individual or knows anything about him or his whereabouts needs to call it in right away,” New York Mayor Bill de Blasio said on CNN.