A small plane crashed into a high-rise building on Manhattan's Upper East Side on Wednesday, sparking a blaze.

The aircraft, either a small plane or a helicopter, hit the 20th floor of a building on Manhattan's East 72nd Street, police sources said.

The crash set off a raging fire that sent a pillar of gray smoke over the city, and flames could be seen shooting from windows on two upper floors of the 50-story building.

There was no immediate word on any deaths or injuries.

Local media said a police spokeswoman confirmed the crash but said she cannot confirm if it is a plane or a helicopter at this time, and the accident is under investigation.

The cause of the crash, which brings back memories of 9/11 terrorist attacks, was not immediately known.