AN M-79 grenade was fired late on Thursday on an auto care shop in a petrol station near the caretaker government's Centre for Maintaining Peace and Order (CMPO), in Lak Si district.
There were no reports of injuries, only property damage.
Police said they were unsure whether the round was aimed at the CMPO, which is located inside the Narcotics Suppression Bureau building on Vibhavadi-Rangsit Road.
The grenade could have been launched from an elevated tollway or from the road heading North, with the shooter on a moving vehicle.
“The motives could stem from conflicts among petrol station staff or politics,” senior commander, Pol Maj-General Suranit Phromebutr, said.
“The shooter could have launched the grenade from a stationary platform if he wanted to target the Sports Club, or he could have aimed at the petrol station,” he said, noting that police had no clues about motives, only statements from witnesses.
The round shot was a highly explosive type, while grenades used in two earlier attacks on the Criminal Court and the Chaeng Wattana protest site were an armour-piercing type, he said.
Separately, a grenade was lobbed at a Siam Commercial Bank branch at Safari World in northern Bangkok, damaging glass windows, kiosks and cash machines, which were still operational as of press time. Police had said earlier that the grenade used was a Russian-made RGD-5, the same sort seized in an arrest by Bang Na police recently.
Meanwhile, a male suspect seen in surveillance footage throwing a grenade at anti-government protesters at Victory Monument rally site last month has been identified.
However, the suspect is believed to have fled to Cambodia, a police source said yesterday.
Krissada Chaikhae, 41, from Kanchanaburi, who lived with his wife and children in Nonthaburi, is wanted for a grenade thrown on January 19, the source said. Police began the process to obtain an warrant for his arrest two weeks ago.
Neighbours in Nonthaburi had identified the suspect, and police were collecting evidence using DNA left on his cap and a shirt he left at the scene when fleeing, he said. The other DNA evidence had been collected from a motorcycle taxi he travelled on to a hideout in Charan Sanitwong Soi 57, the police source said.
After the incident, the suspect fled to Rayong and Chanthaburi. He was then suspected to have crossed over to Cambodia. He may be working as a barber or a cook.