The United Nations envoy to Iraq yesterday called for "calm" in Basra, after six died in the bloodiest day of protests over poor public services in the southern city.
In a statement, Jan Kubis, the UN's special representative in Iraq, called on "the authorities to avoid using disproportionate, lethal force against the demonstrators".
He also urged authorities to "investigate and hold accountable those responsible for the outbreak of violence".
The authorities said in a press conference yesterday that 33 security personnel were wounded in Tuesday's clashes.
Basra was nearly deserted yesterday morning. Many shops were closed, while burned tyres lay strewn across the city's streets, an AFP correspondent said.
The city -- along with the province of the same name -- has been hit by protests since early July against poor public services.
Residents are angry over pollution of the local water supply, which has put 20,000 people in hospital.
The authorities said they would take measures to put an end to the health crisis that has ravaged the oil-rich province.