Five detained over New York explosion

New York was on high alert after an explosion rocked the Chelsea district of Manhattan injuring 29 people, on Saturday night

US federal authorities have reportedly detained five persons with possible links to the New York explosion.

New York was on high alert after an explosion rocked the Chelsea district of Manhattan injuring 29 people, one seriously, on Saturday night.

As reports emerged of the five detained in New York, the FBI's New York branch tweeted that no one had been charged.

"We did a traffic stop of a vehicle of interest in the investigation," the FBI tweet said. "No one has been charged with any crime. The investigation is continuing."

New York media said the five passengers were in custody for questioning. The vehicle was stopped around 9:30 p.m. heading east on the Belt Parkway from the Verrazano-Narrows Bridge, which connects the New York city boroughs Brooklyn and Staten Island, The Telegraph reported.

The New York Daily News reported that weapons were found in the car.

A mystery caller telephoned police hours after a series of bombs were found in Manhattan to warn that there would be more attacks, a local newspaper has reported.

Thousands of people were milling around one of Manhattan's most fashionable areas when the blast ripped through the area shortly after 8:30 p.m. local time.

The blast is understood to have originated from a device placed in a pressure cooker outside the Associated Blind Housing facility at 135 West 23rd Street. A second device was found four blocks away on West 27th Street.

Both bombs in New York were filled with shrapnel and made with pressure cookers, flip phones, Christmas lights and explosive compound, The New York Times reported late Sunday, citing law enforcement officials.

Earlier in the day on Saturday there was an explosion at Seaside Park, New Jersey, which was timed to disrupt a Marine Corps charity run.

An official told Fox News on Sunday that the bombs in New Jersey and New York were "from the same person" and the devices in both explosions included mobile phones.

Bill de Blasio, New York's mayor, said the blast in Chelsea was an "intentional act" but he insisted that there was no credible terrorist threat to the city and there was no link with the New Jersey explosion.

The Joint Terrorism Task Force was called in to investigate the Chelsea blasts well as the New Jersey incident.