NEW YORK - A Marine Corps aircraft's powerful propellers whipped up a wind that sent branches hurtling off a tree and into a crowd of about 150 watching a Memorial Day demonstration in a park, leaving 10 people with cuts and other minor injuries, officials and a witness said.

As the Osprey MV-22 aircraft landed at Staten Island's Clove Lakes Park about 9 a.m. Monday, the wind generated by its twin rotors stirred tree limbs, dirt from a baseball field, and other debris into a swirl that sent spectators scattering, witness Ann Hirsch said.

"It was like a storm of sand and garbage and people running," said Hirsch, 66. "Branches just came down. They were all over the park."

One tree lost all its branches on one side, photographs from the scene show.

The MV-22 is a Marine Corps version of the V-22, wings with rotors that let it take off and land vertically. It "stirs up a lot of wind, and that's apparently what did it," a Marine Corps spokesman, Lt. Josh Diddams, said.

Seven people were taken to a hospital for observation; five of them were released within about two hours, Navy officials said in a release. Three other people refused medical attention, firefighters said.

A joint venture of Boeing Co. in Ridley Township and Textron Inc.'s Bell Helicopter, the V-22 has been plagued by problems in past years, but the aircraft has been deployed to Iraq, and the Marine Corps has called it effective.