The protesters reject the results of last month’s parliamentary elections that saw the pro-Iran militias as the biggest losers.

The health ministry said the injuries in early Friday’s scuffles were mostly from smoke inhalation and rock throwing. Most of the injured were members of the riot police.

It was not clear what sparked the clashes later on Friday.

There were reports of an exchange of fire after dark on Friday following a day of tense rallies and scuffles between the Iraqi forces and the protesters who have been camped out outside the Green Zone for over three weeks.

Iraq’s Prime Minister Mustafa al-Kadhimi ordered an investigation into Friday’s violence to determine what sparked the clashes and who violated orders not to open fire, a statement from the joint security operations room said.

About 300 protesters marched, apparently trying to storm the heavily protected Green Zone, and used rocks to pelt the security forces. The anti-riot police responded with batons, tear gas and water cannons to push them back.

At least 27 civilians and 98 members of the security were injured, the health ministry said. Then clashes erupted, killing at least one protester, two security officials said on condition of anonymity because they were not authorised to speak to reporters.

Following the vote, militia supporters had pitched tents near the Green Zone in an ongoing sit-in, rejecting the election results and threatening violence unless their demands were met.

The United States, the UN Security Council and others have praised the October 10 election, which was mostly violence-free and without major technical glitches.

But unsubstantiated claims of voter fraud have cast a shadow over the vote. The standoff with the militia supporters is also increasing tensions among rival Shiite factions that could reflect on the street and threaten Iraq’s newfound relative stability.

The election was held months ahead of schedule in response to mass protests in late 2019, which saw tens of thousands in Baghdad and predominantly Shiite southern provinces rally against endemic corruption, poor services and unemployment. They also protested against the heavy-handed interference of neighbouring Iran in Iraq’s affairs through Iran-backed militias.

The militias lost popularity since the 2018 vote, when they made big election gains. Many hold them responsible for suppressing the 2019 protests, and for challenging the state’s authority.

The biggest gains were made by influential Shiite cleric Muqtada al-Sadr, who won the largest number of parliament seats, 73 out of 329. While he maintains good relations with Iran, al-Sadr publicly opposes external interference in Iraq’s affairs.

The protests appear to be aimed at pressuring al-Sadr to ensure that Iran-aligned factions are part of the next Cabinet. As the winner, al-Sadr’s bloc will seek coalition partners and name the prime minister.