Bangkok: Three Buddhist teachers were shot dead in two separate attacks in Thailand's Muslim-majority south yesterday, prompting 130 schools to close for fear of further attacks, officials said.

Gunmen shot two female teachers in a government school in Narathiwat, one of three provinces caught up in three years of Muslim separatist unrest in which more than 2,300 people have been killed, police said.

"They got off a motorcycle, walked into the school and killed the teachers in the library while others went out for lunch," a police investigator told Reuters by telephone from the scene.

Police found 11 bullet casings from two pistols near the victims, who were in their 20s and 40s. They had multiple gunshot wounds to the head and torso, he said.

In a nearby district, six men on motorcycles and armed with AK-47 rifles killed a 54-year-old male teacher driving in his car, a police report said.

Education officials immediately ordered 130 schools in the two troubled districts of Narathiwat to close.

"We are afraid of more attacks on teachers," education ministry official Pairach Saengthong told Reuters.

Militants have frequently torched schools and shot teachers - seen as symbols of the largely Buddhist government - in the Malay-speaking region which was annexed by Bangkok a century ago.