At least 29 people are believed to be injured after a loud blast took place in Manhattan, New York, on Saturday night (local time). The explosive device went off behind a dumpster on 23rd street in the Chelsea neighbourhood, shattering windows of nearby cars and buildings. New York City police and fire personnel arrived at the spot shortly afterwards, Reuters reported. A second explosive device is believed to have been found by the police a few blocks away, which appears to be a pressure cooker with wires and phone taped to it.

None of the injuries the victims sustained are life threatening, the city's police commissioner James O'Neill said. However, one person has a puncture wound that might be considered serious, O'Neill added. He said 24 out of the 29 sustained minor cuts and abrasions.

New York City Mayor Bill de Blasio has put the city on alert and said a second site on 27th street is "being treated", though he did not provide further information on the operations at that location. de Blasio said this was being treated as an intentional attack, though there were no inputs to link it to a terror or national security threat.

An official told the New York Times, "We don’t understand the target or the significance of it. It’s by a pile of Dumpsters on a random sidewalk.”

The extent of the damage remains unclear, though the explosion was "ear-shattering" locals said. The city’s police force sent out an alert asking people to avoid 23rd street on Avenues 6 and 7, saying there would be traffic and emergency services in the area. Traffic has been diverted from streets in the area. The United States' Joint Terrorism Task Force has sent its teams to the spot.

The White House put out a statement saying President Barack Obama has been "apprised of the explosion in New York City, the cause of which remains under investigation".

The area where the blast took place is a usually crowded, upscale part of the city.