A communications failure at a Federal Aviation Administration (search) control facility forced some airports in the West to hold flights on the ground Tuesday afternoon, authorities said.

The radio outage occurred at the Los Angeles Air Route Traffic Control Center in Palmdale, in the desert north of Los Angeles, which controls airspace in California and parts of Nevada, FAA spokeswoman Laura Brown said. She said planes were grounded at airports in the Los Angeles region, including those in Orange and San Diego counties, as well as in Las Vegas (search).

Air traffic controllers could monitor the planes on radar but were not able to communicate with them, Brown said. Pilots were forced to switch to a different radio frequency to communicate with other control facilities, she said.

The cause of the problem had not been determined, but authorities were scrambling to identify and fix it, Brown said. Control of the airspace was turned over to other air traffic control facilities, including one in Albuquerque, N.M.

There was no word on when the FAA might lift the order holding planes on the ground.

"We want to stress there are no safety issues, just delays, because control over the air space has been turned over to other air traffic facilities," said Gaby Pacheco, spokeswoman for Los Angeles International Airport.

All flights at San Francisco International Airport (search) destined for Southern California were grounded, said airport spokesman Mike McCarron.

The airport's duty manager, Dennis Neves, said three planes bound for Southern California were diverted to the airport: passenger flights from London and Seattle and a cargo flight from Alaska. Neves said the airport probably would keep the passengers on board the planes and refuel, hoping to wait out the problem.