At least 33 mutilated corpses have been found buried in an area of western Mexico where drug cartels are battling each other, officials have said, the latest in a series of grisly finds amid a scourge of gang-related violence

The bodies, which showed signs of torture, were found in 19 ditches in La Barca, on the border between the states of Michoacan and Jalisco, where a clutch of rival cartels operate. Experts began searching the area based on comments from 25 municipal police who were detained, accused of links to criminal organizations. Some of them had said that corpses of people killed by rival gangs were dumped in the area. Mexico has suffered from a wave of drug-related violence, with about 1,000 people a month dying in gangland killings. About 80,000 people have died since 2007 in cartel violence.