Toxic water in the Tigris river killed thousands of fish and birds in Iraq's Salahudin province, local police told Xinhua on Wednesday.
Residents of Beiji town, 200 km north of Baghdad, said they saw a large number of dead fish floating on the Tigris and hundreds of birds dead for unknown reason since early in the morning, the source said.
"Police stations all over the province reported that an unknown toxic water could be the reason behind the death of the fish and the birds," he said, adding that police vehicles called on the people of Beiji by loudspeakers to stop using the water until further notice.
Samples of the river water have been sent for test to the provincial capital of Tikrit, some 175 km north of Baghdad, and other samples have been sent to local health laboratories to assure the existing and the kind of poison, he said.
The provincial water directorate, which produces drinking water for people in this area, ordered all its projects to suspend working and wait for the tests' results, the source added.
The Tigris flows through Iraq and penetrates eight Iraqi provinces, including Baghdad, before joining Euphrates to form Shatt al-Arab. The river's water is a main source for drinking water supplies for millions of Iraqis.