SACRAMENTO, Calif. (REUTERS) - An airplane crashed during an air show at Travis Air Force Base in California on Sunday, forcing a shutdown of the show, a spokesman for the base said.

The small civilian plane went down during the performance of an "acrobatic aerial manoeuvre" shortly after 2 pm, spokesman Brian Swink said in a statement.

By late afternoon investigators at the scene had not yet released information on whether anyone had been killed or injured, Swink said. He did not say how many people were on the plane.

Base security forces asked any audience members who had taken video or photos of the accident to provide them to investigators, the statement said.

Travis Air Force Base is 47 miles (76 km) north-east of San Francisco in Fairfield, California.