The bodies were found after a shoot-out with suspected drug cartel gunmen in which three gunmen and one marine were killed, the military said.

Found near San Fernando in Tamaulipas state, the corpses are reportedly those of 58 men and 14 women.

The shoot-out near San Fernando happened after an injured man turned up at a navy checkpoint saying he had been attacked by cartel gunmen, Mexican media reported.

Troops raided the ranch, launching an aerial assault. They arrested one underage suspect, military said.

It appears to be among the biggest mass graves linked to drug-related violence to be uncovered in Mexico.

More than 28,000 people have died in drug-related violence in Mexico over the last four years.