Three pipe bombs were found during a routine search of an aqueduct that supplies water to millions of people in Southern California, officials said.

The bombs were found Tuesday next to a valve in a branch of the California Aqueduct, which carries water from the northern part of the state to the southern. It was unclear whether the devices were left there intentionally.

Had they detonated, the devices could have blown open the valve and released water, said California Highway Patrol Sgt. Fernando Contreras. A bomb unit detonated the devices in a safe area.

It is unclear how much damage the bombs could have caused or how they might have affected Southern California's water supply.

Water levels in the aqueduct are periodically lowered to look for submerged items, said Blaine Laumbach, chief operator of the hydroelectric plant that cuts water flow for the searches.

Also found were at least four weapons and 25 vehicles, Contreras said. The cars had probably been stolen and the guns used to commit crimes.

"You can find just about anything in there," he said. "We've found safes from burglaries, soda pop machines, washing machines, all number of things."

Pearblossom is in the Mojave Desert northeast of Los Angeles.