Six police officers have been kidnapped in this northern Mexican metropolis by men armed with assault rifles, authorities said.
Witnesses said several SUV-loads of men armed with assault rifles intercepted two state police vehicles on Friday at an intersection in Monterrey and forced the officers to surrender, sources with the Nuevo Leon Security Council told EFE.
Bullet holes were found in the abandoned police vehicles.
The mass abduction came a few hours after two gunmen were killed and two arrested in a clash with state police in Monterrey, Nuevo Leon's capital, and followed the army's arrest here on Thursday of six traffic policemen on suspicion of ties to organised crime.
Recent months have seen more than 50 attacks on law enforcement personnel and infrastructure in Nuevo Leon, which borders Texas. Authorities blame the violence on a fierce turf battle between the Gulf and Los Zetas drug cartels that has raged since March 2010.