Security has been beefed up in the popular resort cities of Phuket, Krabi and Phang-nga following a tip-off of possible attacks in the area, said Worawit Panprung, police chief of Krabi province on Sunday.
More police officers have been deployed at beaches, tourist attractions and airports, with at least one security checkpoint set up at every police station in the three provinces, he added.
The tip-off came two months ahead of a one-year anniversary of a series of attacks in several provinces in Thailand's south that left four people dead and more than 30 injured in August last year.
The most serious attack was a bomb blast in the busy seaside resort of Hua Hin, which killed one person and injured 20 more. Phuket, Krabi and Phang-nga suffered arson attacks, but no casualties were reported.
Thailand is a predominantly Buddhist country, but a Muslim insurgency in the far south bordering Malaysia has simmered there for decades, with more than 6,500 people killed since 2004.