Police, rescuers and firefighters rushed to the scene near Wat Thong Kung in Phra Pradaeng district after reports of two or three explosions at 7.30am. Firefighters managed to bring the blaze under control at 8.30am.
Inspections revealed that four of the seven boats moored at the pier had been damaged in the incident. There were no reports of injuries or deaths.
Investigators have summoned the owners of the tour boats and the pier for questioning in a bid to trace the cause of the explosion. Mine Mobility Research Co offers a recharging service at the pier, which is owned by Piyasiri Wanit Co.
The electric tour boats were being used for trips in the Gulf of Thailand, according to officials.
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