The killings came as Thai Foreign Minister Kantathi Suphamongkhon, attempting to downplay the unrest to regional partners at an ASEAN meeting in Laos, said the situation in the Muslim-majority south bordering Malaysia had "stabilised".
The attacks, which included the shootings of a former policeman, a civil servant and a village headman, occurred from late Tuesday in three southernmost provinces currently under the thumb of a separatist insurgency and other violence that has left more than 830 dead since January 2004.
Torhea Ngo, a Muslim village headman in Pattani province's Kapho district, was shot dead early on Thursday by motorcycle gunmen while on his way to tap rubber, police there said.
Former border patrol officer Sergeant Major Vichien Kaewthongprakham, 51, was attacked at his home in Khok Pho district in Pattani late Wednesday, resulting in a deadly shootout, police said.
"Vichien was returning home when he was ambushed and slashed by militants. He shot back and killed one attacker before he was shot dead by the other militants," Lieutenant Suthep Chansidam told AFP.
"Vichien was returning home when he was ambushed and slashed by militants"
Thai police officer
Rubber plantation worker Pien Ruengsanga, 65, was shot in the head on Wednesday in Pattani's Mayo district and died in hospital, while state railways worker Sawasdi Buapetch, 42, was shot and killed in Yala province, police said.
"Police initially established the motive of (Sawasdi's) killing as part of the militant unrest campaign," Lieutenant Colonel Thannasit Matyat said.
Muslim Mayueree Mahama, 40, an employee of the Southern Border Provinces Administration in Narathiwat province, died on Wednesday after he was attacked and hit in the head with a wood plank.
And two Buddhist men in Narathiwat's Ra Ngae district were pronounced dead after being shot at in their repair shop by motorcycle gunmen on Tuesday.
Thai Prime Minister Thaksin Shinawatra was to clarify his policy on taming the southern violence in a televised address on Thursday night with the head of an independent commission tasked with formulating a peace plan for the region.