Iraqi police fired in the air as hundreds of protesters tried to storm the main provincial government building in Basra on Sunday, wounding seven demonstrators, police sources said, in unrest over poor state services that has swept southern cities over the past week.
The mounting anger has put Iraqi Prime Minister Haider al-Abadi in a difficult position. He hopes to serve a second term when politicians form a new government following a May 12 parliamentary election tainted by allegations of fraud.
Troubles in Basra have reinforced the widely-held view that Iraqi leaders rarely deliver on promises of a brighter future.
"Some of the protesters tried to storm the building. We prevented them by using water cannons and tear gas," said one of the police sources.
Nineteen security forces were also wounded in clashes with stone-throwing protesters at the provincial government headquarters.
Iraq's top Shi'ite cleric, Grand Ayatollah Ali al-Sistani, has expressed solidarity with protesters, saying they faced an "extreme lack of public services".
Sistani, who has millions of followers, rarely intervenes in politics, but has wide sway over public opinion.
Security forces also faced demonstrations about four km from Eni's Zubair oil field near Basra, a crumbling oil-exporting city. Nineteen protesters were wounded, three by live fire, according to police sources.
Twenty one members of the security forces were wounded after protesters hurled bricks and stones at them.
Internet access in Iraq has been dramatically reduced.
Local officials said demonstrations have not affected crude production in Basra, whose shipments account for more than 95 percent of OPEC producer Iraq's state revenues.
Any disruption could severely impact the country's limping economy and push up global oil prices.