Four policemen were shot dead Wednesday in the southern province of Thailand, Channel Three reported.
The officers on duty were attacked by a group of insurgents in Thung Yang Daeng district while they were searching for smugglers of diesel and gasoline across Thai-Malaysian border in Pattani, reported Xinhua.
Police suspect the attackers were Muslim militants and are investigating the incident.
More than 5,000 people have been killed and over 9,000 injured in Thailand since separatist violence erupted in January 2004, according to Deep South Watch, which monitors the regional violence.