
The first four bombs went off separately near a car show room, a local resident, at parking lot of the SBPAC and near a department store between 9 - 8 a.m. The last of bomb of the day was ignited in the afternoon in front of a stationary shop.
Yala's Muang district police chief Pol. Colonel Phumphet Pipatpetphum said many bomb detonators did not work properly so that they cause low explosion but strong enough to slight damage some properties in their range.
However, the bomb at the SBPAC, which is the coordinator of the southern administration, reflected the loophole in the security system, he said.
The explosion might be a revenge from a militant group under control of Sukree Jehae who was arrested Tuesday, the police said. His men wanted to show they remained strength to play back despite of the arrest of their cell leader, Phumphet said.
Sukree is one of bomb experts who allegedly involved in many explosion in the province including a series of bombs at many commercial banks in the province last year.