MEXICO CITY - Eleven people including four police officers were murdered over the weekend in southern Mexico, the latest in a string of killings ahead of next week's presidential election, officials have said.
Kidnappers killed four policemen in Guerrero state, gagging and shooting three and beheading another.
Local police said the four were kidnapped last week in a remote part of Guerrero state, home to the once glamorous Pacific resort Acapulco, which has become a key front in a battle between drug traffickers and the government.
A police spokesman said a drug gang was thought to be behind the killings.
Another seven murders were reported in Guerrero. The bodies of a businessman and a former police officer were found shot to death in Acapulco and four other bodies were left in plastic bags in Pie de la Cuesta, a beach town on Acapulco's outskirts.
Another shooting victim was discovered bound and wrapped in a black plastic bag in a nearby town, police said.
Drug violence and attacks on police have risen before Mexico's presidential election on July 2, a hotly-contested race leaning slightly in favour of leftist candidate Andres Manuel Lopez Obrador.
Last week, three police officers and a civilian were decapitated in the drug-plagued city of Tijuana on the US border, their heads dumped miles apart from their bodies.
Assailants also launched near simultaneous grenade and machine-gun attacks on at least two police posts near the Guerrero beach resorts of Ixtapa and Zihuatanejo on Saturday, wounding an officer, Mexico City newspaper Milenio reported.