Mexican security forces have discovered 72 corpses on a farm near San Fernando in the north east of the country in what is thought to be the latest incident of drug related violence. Fourteen of the victims are women. Soldiers sent to investigate were caught up in a fire fight, in which one soldier and three suspected gang members were killed. More than 28,000 people have died in drug-related violence in Mexico over the last four years. In June, police recovered 55 bodies from an abandoned mine near Taxco in Guerrerro state.