Federal Aviation Administration spokeswoman Laura Brown said US Airways Flight 1549 had just taken off from LaGuardia Airport enroute to Charlotte, North Carolina, when the crash occurred in the river near 48th Street in New York City.
Brown says the plane, an Airbus 320, appeared to have hit one or more birds.
A law enforcement official said that authorities were not aware of any deaths and that the passengers did not appear to be seriously injured. The official spoke on condition of anonymity because the rescue was still under way.
The plane was submerged in the icy waters up to the windows. Rescue crews had opened the door and were pulling passengers in yellow life vests from the plane. Several boats — including commuter ferries — surrounded the plane, which appeared to be slowly sinking.
Government officials said they did not believe the crash was related to terrorism.
"There is no information at this time to indicate that this is a security-related incident," Homeland Security spokeswoman Laura Keehner said.
Witnesses said the plane's pilot appeared to guide the plane down.
"I see a commercial airliner coming down, looking like it's landing right in the water," said Bob Read, who saw it from his office at the television newsmagazine "Inside Edition."
"This looked like a controlled descent."
New York City firefighters and the U.S. Coast Guard responded to the crash.
"I saw what appeared to be a tail fin of a plane sticking out of the water," said Erica Schietinger, whose office windows at Chelsea Piers look out over the Hudson. "All the boats have sort of circled the area."