There were a series of bomb attacks in Yala on Thursday night, one of which brought down an electricity pole and caused blackouts.
There were two more bombs in the province on Friday, resulting in five policemen being wounded.
Vehicle inspections have been particularly tight on routes heading towards the downtown area of Muang district.
A national security source said the attacks on Thursday were carried out by local units of the Runda Kumpulan Kecil group, especially one led by Isma-ae “Ustaz Soh” Rayarong.