Supplies of the gas are rapidly dwindling in southern Iraq, meaning drinking water will be left untreated within weeks, the UN Children's Fund said.

Nasiriyah, Basra, Zubayr and Safwan are all affected, said Carel de Rooy, the head of the UN agency's office in Iraq, in a written statement.

"Assessments indicate that water plants there will run out of chlorine by the middle of May," he said.

Dirty water could be the final blow to children already weak from malnutrition, UNICEF warned. Temperatures are also on the rise.

Carol Bellamy, UNICEF executive director, underscored that in a three-hour period in Baghdad in the past week, one hospital had reported 300 cases of children admitted with diarrhoea.

"When the supplies of chlorine run out in some areas as early as this week, drawing water from a tap will be like taking it from a swamp," she added.

UNICEF organises the daily trucking of an average of 20 water tanks from Kuwait into Iraq every day.

Diarrhoea and respiratory illnesses already account for 70 percent of deaths among children under five years in Iraq, UNICEF spokesman Marc Vergara told reporters.

He said 400 tonnes of chlorine gas was needed to cover three months, with one tonne needed per million inhabitants per day.

"Without it, we'll see many more child deaths by the end of this month," de Rooy added.

SPACE.WIRE