In a Facebook post, he said a police report on the pollution had been made and investigations were under way.

“The current pollution rate has a reading of one threshold odour number (TON). Water supply will be restored when the reading reaches 0 TON,” he said.

In the meantime, he said, 81 lorry tanks, 34 static tanks and 17 service centres had been mobilised by Air Selangor to help affected users.

Earlier today, Selangor Water Management Authority announced the closure of four water treatment plants as a result of odour pollution in Sungai Selangor.

The Rantau Panjang, SSP1, SSP2 and SSP3 treatment plants were shut down from 12.30am to 2am.

Air Selangor said 1,292 areas in Kuala Lumpur, Petaling, Klang, Shah Alam, Kuala Selangor, Hulu Selangor, Gombak and Kuala Langat are affected by the latest pollution, disrupting supply to 1.19 million users.