The environment department confirmed that damage to a bund silt pond was believed to be caused by sand dredging at Kota Tinggi.

Johor environment department director Famey Yusoff said the state water regulatory body ordered the sand dredging operation to be stopped immediately.

“We have also directed immediate repair work on the bund, but the escaped silt could not be contained as it continued to flow into the river,” he said in a statement today.

Residents and fishermen in Kampung Orang Asli Sayong Pinang, in Kota Tinggi, were distressed when hundreds of fish were found dead due to muddy water in the river, believed to have been caused by the burst pond.

Residents have also lodged police reports and called for immediate action against those responsible.

Contamination of the river has also caused the suspension of operations at water treatment plants along the Johor river.

The state water company Ranhill SAJ said there had been raw water contamination, leading to unplanned water supply disruptions.

The company will also mobilise alternative water supply assistance via tanker trucks to affected areas, as needed.

The affected areas include parts of Senai and Skudai, Seelong and Felda Linggiu, Kulai; Petri Jaya, Kota Tinggi; and Lima Kedai, Iskandar Puteri.