BAGHDAD – Iraqi Prime Minister Adel Abdul Mahdi announced his resignation on Friday after the country’s senior Shi’a Muslim cleric urged lawmakers to reconsider their support for a government rocked by weeks of deadly anti-establishment unrest.

Violence raged on in southern Iraq, however, killing at least 21 people, and protesters continued a thousands-strong sit-in at Tahrir Square in central Baghdad.

Young, unemployed and unarmed protesters have led calls for a rehaul of a political system they say is endemically corrupt and serves foreign powers, especially Baghdad’s ally Tehran.

The departure of Abdul Mahdi could be a blow for Iranian influence after Iran’s militia allies and its own commanders intervened last month to keep the premier in place despite mass anti-government unrest.

The biggest unrest for years in a country struggling to recover from decades of conflict and sanctions pits protesters from Shi’a heartlands in Baghdad and the south against a corrupt Shi’a-dominated ruling elite seen as pawns of Iran.

Iraq’s current political class is drawn mainly from powerful Shi’a politicians, clerics and paramilitary leaders including many who lived in exile before a U.S.-led invasion overthrew Sunni dictator Saddam Hussein in 2003 — including Abdul Mahdi.

“In response to this (the cleric’s) call, and in order to facilitate it as quickly as possible, I will present to parliament a demand (to accept) my resignation from the leadership of the current government,” a statement signed by Abdul Mahdi said.

The statement did not say when he would resign. Parliament is to convene an emergency session on Sunday to discuss the crisis.

Grand Ayatollah Ali al-Sistani earlier urged parliament to considering withdrawing its support for Abdul Mahdi’s government to stem spiraling violence.

Protesters celebrated the imminent departure of Abdul Mahdi, but said they would not stop their demonstrations until the whole of the political class was removed. Violence continued in southern Iraq.

“Abdul Mahdi’s resignation is just the beginning,” said Mustafa Hafidh, a protester at Baghdad’s Tahrir Square. “We’ll stay in the streets until the entire government has gone, and all the rest of the corrupt politicians.”

“It’s not enough,” said Ali al-Sayeda, another demonstrator. “We need them all out, root and branch. We can’t let up the pressure.”

Security forces meanwhile shot dead at least 21 people in the southern city of Nassiriya after protesters tried to storm a local police headquarters, hospital sources said. In Najaf, unidentified armed men shot live rounds at demonstrators, sending dozens scattering.

Iraqi forces have killed nearly 400 mostly young, unarmed demonstrators since mass anti-government protests broke out on Oct. 1. More than a dozen members of the security forces have also died in clashes.

The burning of Iran’s consulate in the holy city of Najaf on Wednesday escalated violence and drew a brutal response from security forces who shot dead more than 60 people nationwide on Thursday.

Sistani, who only weighs in on politics in times of crisis and wields huge influence over public opinion, warned on Friday against an explosion of civil strife and tyranny. He urged government forces to stop killing protesters and protesters themselves to reject all violence.

The government, “appears to have been unable to deal with the events of the past two months…parliament, from which the current government emerged, must reconsider its choices and do what’s in the interest of Iraq,” a representative of Sistani said in a televised sermon.

Protesters, “must not allow peaceful demonstrations to be turned into attacks on property or people,” he said.

Wednesday’s attack on the Iranian consulate in Najaf set off an escalation in violence.

On Thursday, security forces shot dead 46 people in Nassiriya, 18 in Najaf and four in Baghdad.

Friday’s deaths in Nassiriya bring the death toll since Oct. 1 to at least 435, mostly unarmed protesters, according to a Reuters tally from medical and police sources.

Iraq’s “enemies and their apparatuses are trying to sow chaos and infighting to return the country to the age of dictatorship,” Sistani said, without elaborating. “…Everyone must work together to thwart that opportunity.”