BANGKOK, Thailand (AFP) — Assailants detonated bombs at nearly a dozen petrol stations in Thailand’s south early Sunday, injuring four people, the army said, the latest attacks in the insurgency-hit region.

Several bombs exploded within a 40-minute period after midnight on Sunday, igniting 11 petrol stations across Thailand’s southernmost provinces of Narathiwat, Pattani and Yala, an army statement said.

“It happened almost at the same time. A group of an unknown number of men came and detonated bombs which damaged fuel pumps,” Narathiwat Governor Boonchauy Homyamyen told local media, adding that one police officer was injured in the province.

A firefighter and two petrol station employees were injured in Pattani province, the army said.

Thailand’s Prime Minister Anutin Charnvirakul told reporters that security agencies believed the attacks were a “signal” timed with elections for local administrators taking place on Sunday, and “not aimed at insurgency.”