Two bombs exploded in Pattani municipality on Sunday night, one causing minor injuries, and a third time bomb was discovered on Monday morning and was destroyed by the army.
Pattani police chief Pol Maj Gen Santhas Chueaputtarn said on Monday one bomb was detonated in front of the night food market about 8.05pm and another went off in a nearby alley between the Santisook and Palace hotels about five minutes later.
The bombs were hidden in roadside trash bins, he said.
The areas were cordoned off and bomb experts called in to comb the area.
On Monday morning police found another bomb placed near a road intersection on the other side of the city. It was timed to explode at 8pm.
Bomb experts took more than one hour to defuse and dispose of the third bomb.
A woman vendor at the night market was slightly hurt by the bomb that exploded there and at least two parked motorcycles were damaged, according to media reports.
Provincial public relations offices warned residents the explosions served as a warning for people in Pattani and neighbouring Yala and Narathiwat provinces to be watchful for further attacks, especially in commercial centres.