BANGKOK - Four soldiers were killed and two others injured in a drive-by shooting in Thailand's restive southern province of Pattani on Saturday morning, Bangkok Post online reported.

Six soldiers of the No 1532 special task force were patrolling on three motorcycles on the Mayo-Palas road in Pattani's Mayo district when gunmen on three pickup trucks opened fire at them.

The soldiers fired back and the attackers fled the scene after a brief gun battle.

Three soldeirs were killed on the spot and two others were seriously injured and were taken to Mayo hospital.

Police blamed separatist militants for the killing.    

More than 5,000 people have been killed and over 8,400 hurt in the three southernmost provinces of Yala, Pattani and Narathiwat since violence erupted in January 2004, according to Deep South Watch - an agency that monitors the conflict in the southernmost provinces.