A gunman has killed at least four people and injured another nine at festivities in Huehuetan, in the southern Mexican state of Guerrero.
Witnesses described how an armed man walked up to a group of people celebrating the feast of St James the Apostle and shot dead two men and two women, one of them 17.
Police said they had identified the attacker but had not yet been able to apprehend him.
They motive for the attack is unknown.