Police evacuated part of Times Square after finding a suspected car bomb in the busy midtown Manhattan district Saturday night, media reports said.
Officials said it was not considered to be a terrorist threat, and New York City police reportedly asked federal authorities to stand down.
The New York Times quoted an explosives' expert saying it was an improvised device using propane cylinders and powder, but the ignition source 'failed to function the main charge'.
Kevin Barry, a former supervisor in the New York City police bomb squad, speculated that if it had functioned 'it would be more of an incendiary event' than an explosion, the Times reported.
The explosive materials were discovered about 6.30 p.m. by a mounted police officer who saw a box with smoke pouring from it in the back of a Nissan Pathfinder, officials said.