Police gunned down over 100 militants, who stormed more than a dozen security outposts in the bloodiest day yet in Thailand's troubled Muslim-dominated south.
Only five of the security forces were killed. The rest were insurgents, mostly teenagers.
The eight hours of mayhem ended when police fired tear gas and bullets into a mosque in Pattani, killing 34 militants who were holed up inside.
Television news reports showed the bodies of suspected Islamic fighters lying in pools of blood, some of them in front of police stations clasping machetes and wearing coloured shirts and camouflage pants.
Gunfire echoed as armoured personnel carriers cruised deserted village streets and commandos moved through forest.
No group claimed responsibility for the highly coordinated assault by possibly hundreds of young militants, although past violence has been blamed on separatists seeking to carve a homeland in the Muslim-majority south of this predominantly Buddhist country.
Army chief General Chaiyasith Shinawatra said that 107 insurgents were killed and 17 were arrested. He said three policemen and two soldiers were also killed while 15 policemen were wounded.
Soldiers and police - tipped off in advance - were waiting for the poorly armed attackers. Some had guns but most carried only machetes, said chief of police for the south, Lieut General Proong Bunphandung.
"The security officers have been patiently working with local people and gathering intelligence. We waited for the right time to achieve this success," he said. chief of police for the south.
Many parts of the region have been under martial law for months. Security was tightened today along the border with neighbouring Malaysia, which has in the past denied allegations of harbouring militants.
The violence erupted when the insurgents attacked more than 15 police bases, village defence posts and district offices in Yala, Pattani and Songkhla provinces in a bid to steal weapons.