Children killed in Thai school bus shooting

BANGKOK, Thailand (CNN) -- Gunmen attacked a van carrying children to school in a rural province west of Bangkok, killing at least four students and wounding 13, authorities said.

Police said three masked gunmen in camouflage outfits opened fire Tuesday morning with M-16 rifles into a truck converted to a bus for carrying more than two dozen students to school.

The attackers killed students at a local secondary school.

No motive for the attack was immediately known. Witnesses told police the attackers said nothing and made no demands.

The attack took place around 7 a.m. on a rural road in Rajaburi province, about 150 kilometers (95 miles) from Bangkok, and just 10 kilometers (six miles) from the Thailand-Myanmar border. The area has served as a home to ethnic Karen rebels battling Myanmar's military government.