A series of bombs have exploded in the southern Thai town of Hat Yai, in the province of Songkhla, killing at least two people and injuring dozens.
Thai media reported that the bombs, hidden in motorcycles, were triggered by mobile phones at 21:15 local time.
The bombs, two placed at separate department stores and a third near a hotel, exploded simultaneously.
Parts of the southern province are under martial law as authorities struggle with Islamist rebels.
Police and media reports suggested that at least 30 people were injured during the explosions, which took place in busy shopping districts in the city.
"We do believe that the insurgents are responsible for the bombs attacks," a military spokesman said. "Their intention is to spread fear in the region."
Television pictures showed the Odean and Big C department stores on fire as rescue vehicles rushed to the scene.
Worried shoppers also looked on as flames leapt through the Lee Garden Hotel in the city.
The attacks came within hours of a peace rally staged by military forces in the south, where authorities said they hoped people would work with them to halt violence.
Almost 1,700 people have died since the insurgency began in the three southern-most Thai provinces of Pattani, Narathiwat and Yala in January 2004.