Iraq's prime minister has ordered the arrest of anti-government protesters who climbed the walls surrounding Baghdad's fortified Green Zone on Saturday, before storming the parliament building.
A state of emergency was declared in the city after protesters breached the fortified Green Zone, which is also home to most ministries and embassies in the city.
For months, protesters have demonstrated outside the secure area, angry at government deadlock.
The demonstrators are supporters of influential Shiite cleric Muqtada al-Sadr. Sadr has been a vocally opponent to many Iraqi politicians, accusing them of failing to address corruption and waste in the government.
But Saturday marked the first time protesters had breached the fortified barriers securing the Green Zone.
Carrying Iraqi flags and yelling anti-government slogans, the protesters began occupying the main parliament hall.
On Iraqi television, hundreds of protesters were seen taking selfies and chanting as they occupied the building.
Staff with the U.N. Mission Assistance Mission for Iraq, which is headquartered in the Green Zone, said in a statement that they were "gravely concerned" by the security breach.
Officials said the mission "continues to operate from its headquarters in Baghdad's International Zone and is in constant contact with parties to facilitate a solution that meets the demands of the people for reform."
The protesters remained in the parliament late into Saturday night before leaving and gathering in nearby Grand Celebration Square which is inside the Green Zone.
Iraqi Prime Minister Haider al-Abadi has since ordered the protesters be arrested for attacking security forces, lawmakers and damaging property.
Late Sunday, the demonstrators began orderly withdrawing from the Green Zone following announcements by the protest leaders over a speaker system urging them to disband, the Associated Press reported.
Staff with the U.N. and other embassies were said to be on lock down during the security breach, according to Reuters.
Security forces fired tear gas on some demonstrators at one entrance to the Green Zone, the AP reported.
Protester Awad Awadi told Rudaw: "Today the nation has demands. We are demanding our rights."
"We are with the nation," he said. "We are here waiting for the Iraqi people. This represents the Iraqi people."
During a speech in the holy city of Najaf Saturday, Sadr said he could "destroy" the Iraqi government.
Sadr has demanded Iraqi Prime Minister Haider al-Abadi replace ministers and overhaul the government.
"I am promising you that I will not make any agreements with other politicians. I work for the benefit of the nation," Sadr said.
"If the nation lets me I can end the current government and form a new one without any corruption. All the ministers should be changed. I am waiting for the nation to announce a revolution against corruption."
He added: "The government has two choices: either reform or we will destroy it."
Earlier in the week, Iraq's parliament approved a partial cabinet reshuffle proposed by Abadi following mounting public pressure for reform from Sadr and his supporters, Al Jazeera reported.
But the reshuffle has stalled, leading to increased anger from protesters camped outside the Green Zone.