The decapitated bodies of three women and seven men have been found in an abandoned truck in the northern Mexican city of Torreon, police say

One head was found on the windscreen. The others were dumped by the roadside, along with threatening messages. They were found after a night of violence across northern Mexico. National Security Spokesman Alejandro Poire attributed the beheadings to a battle between two drugs gangs, the Zetas and the Sinaloa cartel. Police said that the 10 had probably been killed a few days back, as the bodies were showing signs of decomposition. During the previous night at least 40 people were killed in suspected drug-related violence.