RAUB: Frustration is mounting among villagers in Kampung Sungai Pasu after Sungai Gali, a popular fishing spot, turned black and began emitting a foul smell.

Various species of dead fish have been spotted floating downstream, raising fears of serious water pollution.

Sungai Pasu village headman Mohd Zaidi Hashim said the river, which is usually brownish, turned black several days ago, with dead fish floating on the surface.

"Something is not right with the water... a farmer upstream noticed that the water had turned black on Wednesday but did not suspect anything until various fish species were found dead yesterday.