MEXICO CITY -- Gunmen opened fire during an amateur soccer match in central Mexico on Sunday, killing at least 11 people and wounding 12 others, local authorities said.

The attack occurred around 5:20 p.m. local time (2320 GMT) at a soccer field in the Loma de Flores community in Salamanca, in the central state of Guanajuato. Witnesses said several armed men arrived in two pickup trucks, got out, and fired indiscriminately at players and spectators.

Municipal authorities said 10 people died at the scene, while another victim died later at a hospital. The injured were taken to nearby medical centers for treatment.

The Guanajuato state prosecutor's office said an investigation is underway.

No arrests had been reported as of Sunday night. Security forces, including state police, the National Guard and the Mexican army, have launched an operation to locate the attackers.

Guanajuato has been one of Mexico's most violent states in recent years, with much of the bloodshed attributed to disputes between organized crime groups.