SHAH ALAM: The odour pollution incident which forced four water treatment plants (LRAs) in the state to be shut down temporarily last night was caused by a fuel spill, believed to be diesel from heavy machinery.

State Tourism, Environment, Green Technology and Orang Asli Affairs Committee chairman Hee Loy Sian said the Selangor Water Management Authority's (Luas) investigation along Sungai Selangor found the oil spill at the river bank some 3km away from the Rantau Panjang LRA intake.