Police found a dozen bodies inside a well in northern Mexico, some of them members of a band abducted last week by an armed group, a spokesman for the state of Nuevo Leon, Jorge Domene, said on Monday.
Authorities have identified four of the bodies, including that of a Colombian national. All were wearing jeans and T-shirts with the logo of the music group - "Poderoso Kombo Kolombia."
One band member who managed to escape told police that after he and the others were kidnapped, their armed men captors asked them if they belonged to an organized crime gang. They were shot when they refused to answer.
It was not clear how the surviving band member escaped or whether he was wounded. Domene said he had fled Mexico after reporting the attack.
A total of 18 men, 12 musicians plus staff, were abducted on Thursday at a party in a bar near the industrial city of Monterrey, Domene said.
"Presumably there could be more bodies so we will extend the search as far as conditions allow it," he told a press conference.
Mexican President Enrique Pena Nieto has vowed to reduce criminal violence that spiraled after his predecessor, Felipe Calderon, launched an assault on drug cartels in December 2006. Some 70,000 people have been killed in drug-related violence in Mexico since then.