At least 10 people have been killed in three explosions in the southern Thai province of Yala, officials say.
Yala Governor Dejrat Simsiri said the blasts occurred over 10 minutes at around midday (05:00 GMT) in the commercial district of Yala city.
He said two of the bombs were hidden in motorcycles and the third in a car.
Thailand's three southernmost provinces have been plagued by bomb attacks and shootings since 2004, when a separatist campaign reignited.
"We are not sure which group of suspected Muslim insurgents were behind this, but we are looking," Mr Dejrat said.
Dozens more were wounded.
Thai police told the AFP news agency a policeman had also been injured in a separate motorcycle attack in Mae Lan in neighbouring Pattani province.
More than 4,300 people have been killed in the violence in southern Thailand. As of 2011, the Thai army had 60,000 forces stationed in the region to tackle the insurgency.
The three provinces most affected by the violence - Narathiwat, Yala and Pattani - became part of Thailand in the early 20th Century.
Many of the residents are Muslim and speak a Malay dialect, in contrast with most Thais, who are Buddhist and speak Thai.