A bomb packed on a motorcycle exploded at 6:40 am in an open-air market in Narathiwat province, injuring two policemen and eight civilians.
"We had been warned about bomb attacks but we didn't expect one in the city,” a local official is quoted as saying.
Another bomb went off Monday morning outside a coffee shop at Sugai Koloh, 770 kilometres south of Bangkok, injuring one policeman.
Yesterday the bomb squad defused a seven-kilogram bomb placed in the car of a police officer in Muang district (Yala province).
Experts confirmed the device was remote controlled by a signal sent by a cellphone.
These attacks are but the latest in a string of violent acts that have shaken the provinces of Narathiwat, Pattani and Yala in southern Thailand along the border with Malaysia.
In the past five years about 3,700 people have died in a war pitting the Thai military against a separatist guerrilla.
About 70,000 Buddhists out of 300,000 (in January 2004) have fled the region since rebels raided an army ammunition depot, killing four soldiers and escaping with more than 300 weapons which they have subsequently used in fierce fighting with the military.
Southern Thailand’s Muslim majority has never submitted to rule from Bangkok. They speak a Malaysian dialect and their culture, customs and traditions are Islamic.