Iraq's health ministry has warned the public against buying fish after thousands of dead carp were found floating in the Euphrates river or washed up on its banks, reawakening fears over water pollution that sickened tens of thousands of people in southern Iraq over the summer.
Sections of the river about 80 kilometres south Baghdad were covered with dead fish from nearby farms in the province of Babylon, with authorities using excavators to scoop them out and load them on to trucks.
"The ministry department fears that if infected fish are sold in the markets then thousands of citizens are at risk of disease. This is why we sent a letter to the authorities to prevent the entry of the fish into Baghdad," the director of public heath, Nazek Al Fatlawi, said on Sunday.
An investigation has been opened and samples of river water and dead fish from the province have been collected for testing, which has yet to be completed.
The ministry has been directed "to find out if the cause of the death was due to polluted water or environmental contamination", Mr Al Fatlawi said.
However, the agriculture ministry said its investigation had found that the cause of the deaths was not toxic contamination but bacterial infection, with outbreaks first seen in fish farms east and north of Baghdad in early October.
Agriculture official Safaa Al Junaibi blamed overcrowding of fish tanks, which he said facilitated the rapid spread of bacterial disease.
According statistics compiled by the United Nations' Food and Agriculture Organisation in 2016, Iraq produces 29,000 tonnes of freshwater fish each year.
Water shortages and pollution were among the main issues behind protests that rocked Iraq's southern region since July. The oil hub of Basra is now threatened by a cholera outbreak, according to health officials.
Hospitals in Basra province have treated more 118,000 cases of chronic diarrhoea and other stomach ailments caused by drinking polluted water, according to the Iraq Human Rights Committee.