The protesters, who had gathered outside the heavily fortified district housing government buildings and many foreign embassies, crossed a bridge over the Tigris River chanting: “The cowards ran away!” in apparent reference to departing lawmakers.
There were no reports of clashes with security forces. But an army special forces unit was dispatched with armored vehicles to protect sensitive sites, two security officials said. No curfew has been imposed, they said.
All entrances of Baghdad were shut “as a precautionary measure to maintain the capital’s security,” another security official said.
A United Nations spokesman and Western diplomats based inside the Green Zone said their compounds were locked down. A U.S. embassy spokesman denied reports of evacuation.
Earlier in the day, a suicide bomber drove a truck loaded with three tonnes of explosives into a gathering of Shi’ite pilgrims in the southeastern Baghdad suburb of Nahrawan, killing 19 people and wounding 48 others in an attack claimed by the ultra-hardline Sunni militants.
Sharqiya TV showed Prime Minister Haider al-Abadi walking inside the Green Zone with dozens of armed guards following the breach, discrediting reports he had fled. Protesters later entered the nearby cabinet headquarters.
Such a breach is unprecedented, though only a few years ago mortars frequently rained down on the 10-square-kilometre Green Zone, which once housed the headquarters of the U.S. occupation and before that a palace belonging to Saddam Hussein.
Checkpoints and concrete barriers have blocked bridges and highways leading to the neighborhood for years, symbolizing the isolation of Iraq’s leadership from its people.
Video showed protesters attacking a white, armored SUV with sticks and other objects on Saturday. In separate footage, they beat a man wearing a gray suit.
Sources in Sadr’s office said several Kurdish deputies who had been holed up inside parliament were evacuated by a Sadrist MP in his motorcade.
A Kurdish peshmerga guard at a checkpoint said the protesters surged in after security forces pulled back from an external checkpoint in an unsuccessful effort to secure parliament. They had not been searched before entering the Green Zone, he said.
About ten members of the armed group loyal to Sadr were checking protesters cursorily as government security forces who usually conduct careful searches with bomb-sniffing dogs stood by the side, a Reuters witness said.
Thousands more protesters remained at the gates chanting “Peaceful!”. Some stood atop concrete blast walls that form the district’s outer barrier.
A Sadr spokesman told Reuters the cleric called on supporters to evacuate parliament and set up tents outside.
“Negotiations are ongoing between security and government officials and protesters’ representatives to make sure their demands are met,” said Sheikh Muhanad al-Gharrawi.
President Fuad Massoum called on protesters to leave parliament but added: “Burying the regime of party and sectarian quotas cannot be delayed.”
“GREAT POPULAR UPRISING”
Inside parliament hundreds of protesters danced, waved Iraqi flags and chanted pro-Sadr slogans. Some appeared to be breaking furniture.
Rudaw TV showed them chanting and taking pictures of themselves inside the main chamber where moments earlier lawmakers had met.
Parliament failed to reach quorum earlier on Saturday to complete voting on a cabinet reshuffle proposed by Abadi after a handful of ministers were approved on Tuesday despite disruptions by dissenting lawmakers.
Political parties have resisted Abadi’s efforts to replace some ministers – chosen to balance Iraq’s divisions along party, ethnic and sectarian lines – with technocrats in order to combat corruption.
Supporters of Sadr, whose fighters once ran swathes of Baghdad and helped defend the capital from Islamic State in 2014, have been demonstrating in Baghdad for weeks, responding to their leader’s call to put pressure on Abadi to follow through on months-old reform promises.
Moments before the Green Zone breach, Sadr seemed to offer an ultimatum: “Either corrupt (officials) and quotas remain or the entire government will be brought down and no one will be exempt from that.”
In a televised speech from the holy city of Najaf announcing a two-month withdrawal from public life, Sadr said he was “waiting for the great popular uprising and the major revolution to stop the march of the corrupt.”
Abadi has warned that delays to overhauling the cabinet could hamper the war against Islamic State, which controls vast swathes of northern and western Iraq.