Gunmen have opened fire on a school bus near Thailand's border with Burma killing at least four children and wounding another 13. Officials said the attack took place in Ratchaburi province on a road 100 kilometres (62 miles) west of the capital, Bangkok. Three men opened fire with M-16 rifles on the bus, which was carrying more than 20 children from the Ban Kha Witthaya secondary school, just after 0700 on Tuesday (midnight GMT). The driver of the bus managed to swerve away from the gunmen, who stepped out in front of it and sprayed it with bullets. "I heard a series of loud shots and many of my friends were hit," a 13-year-old girl told a radio station. "My school uniform was splattered with their blood."