Nine people, including a child, were feared killed when a helicopter carrying Italian tourists collided with a light plane over New York's Hudson River.

New York Mayor Michael Bloomberg said two bodies had been pulled from the Hudson and that police divers did not expect to find survivors after the accident, which took place in full view of horrified residents.

"This is not going to have a happy ending," Bloomberg said.

Helicopter crashed with light plane over New York's Hudson River The Eurocopter AS350 was carrying five Italian tourists and a pilot. Two passengers, including one child, plus a pilot were aboard the single-propeller Piper PA32 plane, the mayor said.

"At this point we have found two bodies," Bloomberg told a press conference. "One we believe was floating free and the other the divers have recovered."

Bloomberg called the incident "not survivable," adding: "This has changed from a rescue into a recovery mission."

The collision took place just after noon (12 midnight Malaysian time) on a hot summer day when river-front streets were crowded with locals and tourists.

Helicopter crashed with light plane over New York's Hudson River Witnesses described the two aircraft plummeting into the river between Manhattan and New Jersey.

"It hit the water like a stone," a woman told NY1. "I saw a piece of metal, I saw a helicopter, the helicopter went down, and that was it. I heard no noise, and no smoke or fire."

Some witnesses said the accident had been almost noiseless, but others reported hearing either the collision or impact against the river.

"We heard a really loud crash which sounded like lightening or thunder," another woman said. "They were both falling from the sky."

Witnesses also spoke of seeing debris - either part of the plane's wing or fragment of the chopper's rotor - fluttering down.

Densely crowded air corridor

New York state Governor David Paterson offered the bereaved his condolences.

"What began as a beautiful day with blue skies has turned into a day of darkness for those who lost someone they love today," he said.

Immediately after the accident, rescue craft rushed to the scene. However, it soon became clear that they had little to do.

An initial US Coast Guard report of one person recovered turned out to be premature.

The National Transportation Safety Board said it had sent investigators to New York.

Helicopter crashed with light plane over New York's Hudson River However the difficulty faced by divers locating wreckage of the aircraft in the fast-flowing Hudson was likely to delay the investigation.

Bloomberg said divers had found one large piece of wreckage, but were proceeding cautiously in poor visibility and dangerous currents.

Officials said the light plane had taken off from Teterboro Airport in New Jersey, while the helicopter belonged to a company providing flights for tourists.

Their collision took place in a densely crowded air corridor used by commercial flights, private pilots and tourist helicopters.

New Jersey Governor Jon Corzine called the accident "devastating" and said that safety measures needed checking.

"All of us in this region also need to take a long and serious look at the circumstances surrounding this crash to ensure that significant air traffic over the Hudson doesn't come at the risk of the safety of New Jersey families who live along the riverfront," he said.

This January an Airbus jet operated by US Airways lost power over New York but the pilot made a successful splash landing in the Hudson, just off Manhattan, with no loss of life.

The accident was caused after the airliner hit a flock of wild geese, resulting in both engines to be disabled.