MEXICO CITY (AP) — Forensic scientists in the Mexican state of Sonora have recovered 10 bodies from mass graves near a beach town, raising the total number of bodies and skeletons found in the area since October to 52.

The state attorney's office said Saturday they were tipped off to the desert burial pits by a group of volunteers called Searching Mothers that tries to find missing people.

The bodies were found near the Gulf of California beach town of Puerto Penasco, known to U.S. tourists as Rocky Point.

Authorities began pulling human remains from the burial pits at the end of October. Mexican forensic personnel are conducting autopsies.

Drug and kidnapping gangs often bury the bodies of people they have killed in such clandestine sites.