Twelve Mexican police officers were ambushed and killed near a remote southern town where locals earlier found 10 human heads, prosecutors said Monday. The officers were ambushed on a highway Sunday hours after the heads of seven men and three women were found near a slaughterhouse in the mountain town of Teloloapan, an official with the Guerrero state attorney general\'s office told AFP. \"A convoy of state and municipal police that was on patrol was attacked, and sadly 12 police officers died,\" Guerrero state security spokesman Arturo Martinez Nunez later told local media. Eleven other police officers were wounded in the attack, Martinez said. Martinez Nunez blamed the attack on organized crime, but did not name suspects. The region has been marked by clashes between the La Familia cartel and a group known as the Knights Templar. Near the decapitated heads, police found a message warning anyone who helped La Familia. The rest of their bodies have not been found, officials said. The Templars split from La Familia in early 2011, and the two have been engaged ever since in a turf battle in parts of Guerrero and nearby Michoacan. Both groups have local autonomy, but experts say they are allied with powerful rival drug cartels: the Knights Templar are allied with the Sinaloa drug cartel led by Joaquin \"Chapo\" (\"Shorty\") Guzman, while La Familia is allied with Los Zetas, the violent cartel made of former elite Mexican commandos. Soldiers, federal, state and local police launched a vast operation looking for the killers Sunday after the heads were found. The police killed in the ambush, a mix of local and state officers, were surprised by heavily armed gunmen, law enforcement officials said. A Teloloapan police official told AFP by telephone that the town\'s 21,500 residents had been terrified by the killings. More than 50,000 people have been killed in Mexico\'s war against drug cartels since President Felipe Calderon mobilized his army in December 2006 to help police fight against the criminal organizations.