Concerns raised by people living along the Pasak River in Lopburi’s Chai Badan district about its shocking change in colour to a queasy shade of green were amplified by Thai netizens on Friday.
Local residents and online commentators expressed alarm that the abnormally coloured water might damage the ecosystem.
They urged government officials to investigate to find out why the water turned murky green and whether it is a signal of an ecosystem in distress.
Thai-language media reports say the colour of the river changed near Ban Tha Samae San and Ban Tha Din Dam communities because of stains on its surface.
A local fisherman was quoted as saying the water turned a murky shade of green four or five days ago. He said the change in colour did not result in dead fish or a foul odour.
He did, however, express concern that the murky green water could damage the ecosystem and called for officials to investigate.
The 570-kilometre Pa Sak River flows through central Thailand. It originates in Loei’s Dan Sai district and passes Phetchabun, Lopburi and Saraburi before merging with the Lopburi River in Ayutthaya.