Authorities in central Mexico say a clash between security forces and gunmen armed with AR-15 rifles and grenades left 10 assailants dead.

The attorney general for justice in Mexico state, Miguel Angel Contreras Nieto, said Tuesday that 10 commandos attacked a convoy of Mexican soldiers and state police near Valle de Bravo and Otzoloapan in the central state.

He said that the gunmen were killed in the resulting fighting. Troops found grenade launchers, grenades and AR-15 rifles.

Contreras Nieto declined to give more details or say if the gunmen belonged to a drug cartel, adding that "investigations were continuing."

President Enrique Pena Nieto was governor of Mexico state before assuming top office and has promised to quell drug-related violence.