TRACY, Calif. —  The FBI has joined the search for a California girl who hasn't been seen since Friday night.

FBI agents, Tracy police and officers from about a dozen law enforcement agencies are looking for eight-year-old Sandra Cantu, authorities said.

Sandra hasn't been seen since around 4:00 Friday afternoon when a surveillance video camera recorded her walking away from her family's mobile home. Her mother reported her missing at about 8 p.m..

Throughout the day Sunday, police searched homes in the mobile home park, while volunteers went door-to-door with fliers.

A police spokesman said investigators did question one man in the park, though they said there is no indication of foul play.

A $2,000 reward is being offered by the FBI and Tracy Crime Stoppers for information concerning Sandra's whereabouts.