PHAYAO -- People from Ban Na-om in tambon Khun Khuan of Pong district have flocked to the nearby Khuan River since a fisherman noticed gas bubbling up to the surface.
Seksan Jaikwang, 29, said the gas bubbled up after he stuck a bamboo pole into the muddy river bed. Out of curiosity he applied a flame to the gas, and it quickly caught fire.
His discovery drew villagers to the spot, which is in front of Wang Chan dam, where Khang and Sao streams meet to form the Khuan river.
Pong district chief Jaran Kanchanapanyanond said he reported the unusual incident to the deputy provincial governor, Sorathorn Santhad, who subsequently instructed the provincial natural resources office to inform the Regional Environment Office in Lampang.
The office would send officials to observe the phenomenon on Wednesday, he said.
The district chief said his first thought was that it is methane gas generated by leaves that have accummulated on the river bed over a long time and started decomposing..