Monterrey (Mexico), Dec 6 (EFE) A group of gunmen attacked a detention centre in the northern Mexican state of Nuevo Leon, freeing 23 inmates and killing two federal agents guarding the facility.
State police said a group of more than 20 gunmen Friday attacked the detention center in Escobedo, part of the Monterrey metropolitan area, and killed federal agents Roberto Gonzalez Barco, 33, and Ricardo Mota, 42.

They then proceeded to free 23 inmates. Among them were several former police officers in the town of Garcia suspected in the recent murder of that municipality’s police chief, Gen. Juan Arturo Esparza.

Eyewitnesses told reporters that the inmates freed in the attack were whisked away in at least five vehicles.

State investigators, federal police and army soldiers arrived on the scene after the attack.

Earlier Friday, 13 people died in Monterrey in a series of clashes between Mexican army troops and dozens of gunmen.

The confrontation began in the Monterrey suburb of Juarez after soldiers went to a ranch where they suspected that kidnappers were holed up with several captives, a participant in the events told EFE.

The troops were met with heavy fire from around 50 heavily armed men thought to be drug-cartel enforcers, the military source said.

Seven suspects were killed in the exchange and nine others taken into custody, but the rest fled in more than a dozen vehicles.

While making their escape, they ran into a contingent of 30 soldiers sent to support the first unit, and another battle ensued, the source said.

Five gunmen and one civilian died in the second clash, which took place at the intersection of two major highways. Six other people - three suspects and three motorists - were taken to hospitals with injuries, the military source said.

The remaining gunmen managed to get away.

Among the gunmen killed in the shootouts was Ricardo Almanza, alias “El Gori,” the chief suspect in the November slaying of Esparza. A 30-million-peso ($2.3 million) reward had been offered for information leading to his capture.

Monterrey is a major industrial city and the capital of Nuevo Leon, one of the battlegrounds in a turf war among Mexico’s powerful drug cartels.