All the schools have been closed indefinitely in Raman district, Yala province, where elementary school principal Weera Mueanchan was gunned down after classes on Wednesday , a local education official said.

His death came after a series of attacks on targets linked to schools in provinces along the southern border with Malaysia, including the killing of a bus driver and parents dropping off their children.

“There are 55 schools in Raman district -- mostly elementary schools and one secondary school. They have been shut down indefinitely because teachers fear of their safety after yesterday’s killing,” the education official said.

The teachers’ union plans to meet to discuss how to improve security, but no date has been set, he added.

Schools and teachers are frequent targets of attack, because militants see the education system as an effort by Bangkok to impose Buddhist Thai culture on a region that is mainly Muslim and ethnic Malay.

More than 3,300 people have been killed since separatist unrest broke out in January 2004 in the south, which was an autonomous Malay Muslim sultanate until Thailand annexed it in 1902, provoking decades of tension.