Moqtada al-Sadr speaks to the media in Najaf, Iraq, on Saturday. Photograph: Anmar Khalil/AP
Sadr and his supporters want the political system, put in place following the US-led invasion in 2003, to be reformed. As it stands, entrenched political blocs representing the countrys Shias, Sunnis and Kurds rely on patronage, resulting in widespread corruption and poor public services. The major blocs have until now blocked Abadis reform efforts.
On Sunday, protesters vowed to continue their sit-in inside the green zone until their demands are met.
We are fed up, we are living a humiliated life, Rasool Hassan, 37, said from the square inside the green zone where thousands of protesters had gathered. Well leave here only when the corrupt government is replaced with another of independent technocrats that serves the people not the political parties.
We need new faces, not the old ones, said Shatha Jumaa, 58, a surgeon. Jumaa, who identified herself as secular, said she wanted the government dissolved and replaced by a small interim administration whose job would be to amend the constitution and to prepare for an early election.
Iraq has been mired in political crisis for months, hindering the governments ability to combat Islamic State, which still controls much of the countrys north and west, or address a financial crisis largely prompted by the plunge in global oil prices.
Iraqi security forces initially responded to Saturdays events by tightening security across the capital, sealing off checkpoints leading to the green zone and stopping traffic on main roads into the city.
The UN mission to Iraq said it was gravely concerned. It issued a statement condemning violence against elected officials and urging calm, restraint and respect for Iraqs constitutional institutions at this crucial juncture.