Protesters in the southern Iraqi city of Basra have set fire to the main government building, a day after six people were killed in demonstrations over poor public services.
The blaze was started after security forces opened fire on protesters as the two sides clashed, The New Arab's Arabic-language service reported.
"Security forces have pushed protesters to start the fire by their use of excessive force and live bullets," one protester said.
"It is as if they are fighting terrorists and not their own people," he added.
Police fired gunshots and tear gas directly at the demonstrators, who had gathered in their thousands outside the regional government headquarters.
The measures failed to disperse protesters, who responded by hurling Molotov cocktails and setting off fireworks at the security forces.
On Tuesday, six demonstrators were killed and more than 20 wounded during the bloodiest day of clashes with security officials, a local official and medics said.
The authorities said that 30 security personnel were also wounded in the violence "by grenades and incendiary objects".
Iraq's oil-rich city of Basra and other cities in the southern Shia heartland have been brewing since July over endemic corruption, soaring joblessness and poor public services
Residents are particularly angry over pollution of the local water supply, which has put 20,000 people in hospital.
Iraq's prime minister has ordered an investigation into the violent protests.
Haider al-Abadi has said he had ordered "no real bullets... to be fired, in the direction of protesters or in the air".
The United Nations envoy to Iraq had called for "calm" in Basra ahead of Wednesday's clashes and urged the authorities "to avoid using disproportionate, lethal force against the demonstrators".
The UN's Jan Kubis also asked the government to "investigate and hold accountable those responsible for the outbreak of violence" and "do its utmost to respond to the people's rightful demands of clean water and electricity supplies".