OAKLAND, Calif. -- Contra Costa County sheriff's deputies served a search warrant at a home in West Oakland early Wednesday as part of an investigation into the theft of five sheriff's weapons earlier this week, a sheriff's spokesman said.

Investigators conducted the search at about 1:30 a.m. but did not recover the weapons, Contra Costa County sheriff's spokesman Jimmy Lee said.

A probation search was also conducted and several people were interviewed, but no arrests were made, Lee said.

The weapons, three rifles and two shotguns, were stolen from sheriff's office vehicles in Martinez and Richmond late Monday night or early Tuesday.

According to Lee, a suspect or suspects cut through a fence and broke into what was thought to be a secure parking lot in the 1900 block of Muir Road in Martinez.

The suspect or suspects ransacked three sheriff's patrol vehicles and two vans, taking three AR-15 rifles and one shotgun, Lee said.

Around the same time, someone broke into a sheriff's patrol vehicle at the Bay Station in Richmond and stole a shotgun from a sheriff's patrol vehicle, Lee said.

Lee said it is not clear whether the same people were responsible for both burglaries.

He said the sheriff's office is working with other law enforcement agencies to identify suspects.

"We have contacted local agencies, including the CHP, which had a similar theft about a month ago," Lee said.

In December, a burglar cut a chain-link fence surrounding a California Highway Patrol lot in Martinez and stole a tactical rifle and ammunition out of a CHP patrol car.

The CHP lot, located at 5001 Blum Road, is about a mile from the sheriff's office lot.

The patrol cars were parked about 50 feet from the office, which is staffed 24 hours a day, but the burglar somehow managed to remain undetected despite motion-sensor lights in the lot, according to the CHP.

The sheriff's office is working with the CHP to find the burglars, but have not yet determined whether the same person or people are responsible in the two thefts.