Mexican authorities say a U.S. man has died in a shark attack off Mexico's southern Pacific coast.

The government of the southern state of Guerrero said on Tuesday that the surfer from San Francisco has bled to death after a gray shark bit his thigh, leaving a 15-inch wound.

The U.S. embassy in Mexico is not confirming the man's name, but local authorities have identified him as a 24-year-old who was surfing with a fellow American.

The attack occurred Monday at the Troncones beach, about 60 miles (100 kilometers) west of the beach resort of Ixtapa.