Riot police fire tear gas to disperse protesters at the Al Shuhada (Martyrs) bridge in Baghdad on Thursday. AP

Iraqi security forces shot dead at least six anti-government protesters in Baghdad on Thursday and killed four others as they broke up a sit-in in the southern city of Basra, police and medical sources said.

Scores more were wounded in the clashes as weeks of deadly violence in Iraq over protests against an entrenched political elite showed no signs of abating.

Security forces used live fire against protesters near Shuhada Bridge in central Baghdad. Gunfire was used against demonstrators in Basra, the main source of Iraq's oil wealth, who had staged a days-long sit-in.

Eleven people killed in southern Iraq protests overnight

Iraqi security forces use live fire to disperse Baghdad protesters

Elsewhere in southern Iraq, dozens of protesters burned tyres and blocked the entrance to the port of Umm Qasr, preventing lorries from transporting food imports, just hours after operations had resumed, port officials said.

The Iraqi government has failed to find a way out of the biggest and most complicated challenge it has faced in years. The unrest has shattered the relative calm that followed the defeat of Daesh in 2017.

Iraqi protesters burn tires as they block the entrance to Umm Qasr Port, Iraq, on Thursday. Essam Al Sudani/Reuters

A crackdown by authorities against mostly unarmed protesters has killed more than 260 people since demonstrations began on Oct. 1 over lack of jobs, chronic power and clean water shortages, poor education and healthcare and corruption.

Protesters, mostly unemployed youths, blame a political elite that has ruled Iraq since the toppling of Saddam Hussein in 2003, and demand a complete overhaul of the political system.

The economy is beginning to feel the pinch.

Internet outages imposed by the government to try to stem unrest have hit the private sector, a central bank source said.

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Death toll soars as protests rage in Iraq

Protesters, mostly unemployed youth, blame a political elite that has ruled Iraq since the toppling of dictator Saddam Hussein in a 2003 US-led invasion, and demand a complete overhaul of the political system.

Trucks prepare to leave the port of Umm Qasr on Thursday. AP

The country is beginning to feel the fiscal pinch of weeks of the unrest, which started in Baghdad and quickly spread to southern cities.

The new stoppage of operations at Umm Qasr port in the south is likely to compound financial losses a day after the government said that a week-long halt of operations there had cost more than $6 billion.

Umm Qasr briefly resumed operations early on Thursday after most protesters cleared the area. But several dozen activists, relatives of a demonstrator killed during weeks of violence, then returned to block the main gate, port officials said.

Umm Qasr receives most of the grain, vegetable oils and sugar that Iraq depends upon.