Part of the main entrance wall and guard post at the Bukit Tengah police station here were damaged after "mercun bola" (high exploding firecrackers) were hurled there by unknown suspects early today.

Penang Deputy CID chief ACP Nasir Salleh said four policemen were on duty at the station in the 4.50am incident but all were unhurt.

"Two of the policemen were inside while the other two were making their rounds in the compound, they only realised what happened on hearing loud sounds at the entrance pf the station.

"On checking, they found several window panes at the guard post broken and damage inflicted on the entrance wall," he told reporters at the scene.

He estimated damage to be between RM10,000 and RM15,000.

"Based on initial investigations, several suspects on motorcycles had hurled "mercun bola" that had been tied together (for a bigger bang) at the entrance of the police station before fleeing. Everything happened very fast," said.

Nasir said police were not sure of the motive for the attack and that investigations were ongoing.

"There is no CCTV at this police station but we will get recordings from CCTVs located in the area," he added.

The case has been classified under Section 5 of the Explosives and Corrosive Substances Act.

Anyone with information on the case is urged to contact DSP Aziz Ahmad at the Seberang Perai Tengah police station at 04-5382222 or the nearest police station.