Mexican authorities say seven heavily armed men ambushed a pickup truck and killed the four men inside in the Pacific coast state of Guerrero.

The state's public safety department says four men were driving through the municipality of Zirandaro de los Chavez Monday morning when the attackers opened fire.

Zirandaro de los Chavez is in an isolated mountainous zone, known as Tierra Caliente, that is plagued by drug violence.

More than 15,000 people have died in drug violence nationwide since Mexico began a crackdown on cartels in December 2006.