Updated

A prosecutor in southern Mexico says one of two priests shot to death in a road ambush had been photographed earlier holding an assault rifle in the company of armed, masked men.

The head prosecutor for Guerrero state says the two priests went to an open-air concert attended by members of various drug gangs.

Prosecutor Xavier Olea said Tuesday there was a fight at the concert involving the priests' group of acquaintances and the priests were apparently killed by gunmen of a rival gang.

The two were shot to death along with four other people when gunmen opened fire on their truck Monday.

Olea says the photograph of the priest with the assault rifle led the gunmen to think he was associated with a rival gang.