On Monday night, unidentified attackers used Molotov cocktails to set fire to a logging factory in Yala province, said police Lt Col Parinya Kwanyeun.
A worker, Kek Pinlamai, 49, who rushed out to confront the attackers was shot dead, he said.
A police force that arrived to investigate was ambushed by the attackers and a 10-minute firefight ensued but there were no casualties from either side, Parinya said.
Also in Yala, six other deserted buildings were set on fire Monday night, he said.
In other pre-dawn attacks on Tuesday, a house belonging to the Forest Department, an unoccupied house and a 10-wheel truck were set on fire in Pattani, said police Lt Nantachai Janpho.
A bomb blast on Saturday night in the border town of Sungai Kolok, which injured about 30 people, has severely affected tourism in the area, said Abudulyahi Hawareluemare president of Narathiwat Tourist Agency Association.
At least 30,000 tourists from Malaysia and Singapore have cancelled their plan to celebrate Songkran water festival in Narathiwat, he said.
Thai Muslims complain of
The three affected southern Thai provinces in addition to the relatively peaceful Satun province are the only Muslim majority areas in this predominantly Buddhist country.
At least 56 people - mostly policemen, teachers and government officials from the country's Buddhist majority - have been killed this year in attacks in Narathiwat, Pattani and Yala provinces in a revival of an Islamic separatist movement that was quashed in the 1980s.
Thai Muslims have long complained of discrimination in jobs and education by the central government in Buddhist-majority Thailand. They also say their culture and language are being suppressed.
Police last week accused Najm al-Deen Umar, a Muslim
lawmaker of the ruling Thai Rak Thai party, of masterminding the attacks.
Police sent Parliament a letter asking it to lift Najm al-Deen's
parliamentary immunity so that officers can arrest him, Deputy House Speaker Somsak Prisana-anantakul said on Tuesday.
He said the letters list the charges against Najm al-Deen, including mobilising an armed force, gathering firearms for treasonous acts, conspiring in a plot to achieve separatism, and associated crimes.
The issue will likely be debated by the 500-member house next week, the deputy speaker said. Najamudeen was not immediately available for comment.