The recent selection of Mohammed al-Sudani as the official nominee of a coalition led by Tehran-backed Shiite parties sparked Wednesday's demonstrations in Baghdad.
Hundreds of Iraqi protesters breached Baghdad's Green Zone parliament on Wednesday chanting anti-Iran curses in a demonstration against a nominee for prime minister by Tehran-backed parties.
Most of the protesters were said to be followers of influential Shiite cleric Muqtada al-Sadr.
The demonstrators were seen singing and waving Iraqi flags, while some walked on tables on the parliament floor, leafed through folders, and sat in lawmakers' chairs. The incident raised the stakes in the political struggle for Iraq nearly 10 months after federal elections.
No MP were present, with only security forces inside the building, but the protest did not escalate into outright violence.
The spark behind the demonstrations was the recent selection of Mohammed al-Sudani as the official nominee of the Coordination Framework bloc -- a coalition led by Iran-backed Shiite parties and their allies.
It was the largest protest since federal elections were held in October and the second time al-Sadr has used his ability to mobilise the masses to send a message to his political rivals this month.
Earlier in July, thousands heeded his call for mass prayer, an event many feared would devolve into crowds demonstrating in the streets.
Hours after his followers occupied parliament, al-Sadr issued a statement on Twitter telling them their message had been received and "to return safely to your homes," signalling there would be no further escalation of the sit-in.
Shortly after, protesters began making their way out of the parliament building with security forces supervising.
A repeat of 2016 parliament breach
The incident, and al-Sadr's subsequent show of control over his followers, carried an implicit warning to the Framework alliance of a potential escalation to come if the government forms with al-Sudani at the helm.
Al-Sadr's ability to mobilise and control his large grassroots following gives him powerful leverage over his rivals. Similarly, his followers stormed the Green Zone in 2016 and entered the country's parliament building to demand political reform.
Earlier in the day, demonstrators breached Baghdad's heavily fortified Green Zone, which houses the parliament and other government buildings and foreign embassies.
Protesters chanted curses against Iran and said, "Sudani, out!"
Riot police had attempted to repel the protesters using water cannons, but demonstrators scaled the cement barrier walls and pulled down slabs using ropes to enter the Green Zone.
The demonstrators walked down the zone's main thoroughfare with little resistance from security forces. One security personnel was seen handing a protester a water bottle.
Caretaker Prime Minister Mustafa al-Kadhimi called for calm and restraint and protesters to "immediately withdraw" from the area.
Al-Sadr recently stepped down from the political process despite winning the most seats in the October federal election. Protesters carried portraits of the cleric.
Al-Sudani was selected by State of Law leader and former premier Nouri al-Maliki. Before al-Sudani can face parliament to be seated officially as a premier-designate, parties must first select a president. "Maliki, garbage," protesters also chanted.
The Framework, in a statement, said they had known of "calls urging chaos, stirring up strife," within the last 24 hours since nominating al-Sudani.
The United Nations said Iraqis had the right to protest but that it was "essential that demonstrations remain peaceful and comply with the law," in a statement.
Al-Sadr exited government formation talks after he could not corral enough lawmakers to get the majority required to elect Iraq's next president.
By replacing his lawmakers, the Framework leader pushed ahead to form the next government. Many fear doing so also opens the doors to street protests organised by al-Sadr's large grassroots following and instability.