Iraq's powerful Shiite Muslim cleric Muqtada al-Sadr on Monday announced his withdrawal from politics and the closure of his institutions over the political deadlock in the country. The move prompted violent clashes across Baghdad that left at least 15 people dead.

"I've decided not to meddle in political affairs. I therefore announce now my definitive retirement," al-Sadr said in a statement on Twitter. He also said "if I die or get killed, I ask for your prayers."

Al-Sadr, a longtime player in the Middle East nation's political scene, criticized fellow Shiite political leaders for failing to act upon his calls for reform.

Without elaborating on the closure of his offices, al-Sadr said that some of his cultural and religious institutions would remain open.

As news of the violence caused by clashes between his supporters and rival groups began to spread, al-Sadr announced that he was beginning a hunger strike until the clashes ceased.

Al-Sadr supporters break into Republican Palace

His announcement was followed by hundreds of his supporters rushing to the government palace, which houses the main offices of Iraq's caretaker Prime Minister Mustafa al-Kadhimi. Kadhimi said he was suspending all cabinet meetings until further notice.

Protesters used ropes to pull down cement barriers leading to the seat of the government, prompting Iraq’s military to call for an immediate withdrawal from the Green Zone. The military urged protesters to practice self-restraint "to prevent clashes or the spilling of Iraqi blood," according to a statement.

"The security forces affirm their responsibility to protect government institutions, international missions, public and private properties," the statement said.

The army then announced it was imposing a 3:30 p.m. curfew for all of Baghdad, but that did little to deter al-Sadr's followers, who pushed into the Republican Palace chanting "the people want to overthrow the regime."

Violence spreads outside Green Zone

As the situation escalated, the curfew was later extended, with all of Iraq required to be indoors by 7 p.m. Witnesses told reporters that they heard live fire and saw security services use tear gas inside the fortified Green Zone.

Outside the Green Zone government compounds and embassies, dozens of young men loyal to al-Sadr and supporters of a rival Shiite group, the pro-Iran Coordination Framework, hurled stones at each other in street clashes.

Later, police and medical personnel said that at least ten people had died and that 85 were injured as the violence spread and witnesses said they could hear gunfire in different parts of the city.

There were also reports that protests had spread outside of Baghdad, including demonstrators blocking access to the airport in key port city of Umm Qasr, 560 km (350 miles) from the capital.

The AFP news agency reported, citing an unnamed security source, that at least seven shells fell in the Green Zone. The report could not be independently verified, and it was not clear who was behind the reported shelling.

White House spokesman John Kirby told reporters that the US was not evacuating its embassy in Iraq. He urged calm in the country, saying "now is the time for dialogue, not confrontation."

"Reports today of unrest throughout Iraq are disturbing....  We urge those involved to remain calm, to abstain from this violence and pursue peaceful avenues of redress," he added.

According to state media in neighboring Kuwait, however, their government was urging all its citizens in Iraq to leave.

Why is there political deadlock in Iraq?

Despite winning the largest share of seats in last October's elections, a political impasse between al-Sadr and his Iran-linked Shiite rivals has given Iraq its longest run without a government. In June, he withdrew his lawmakers from the parliament after failing to form a government of his choosing. 

Since last month, his supporters have occupied parliament and held protests near government buildings. With the process of choosing a new president and prime minister halted, many fear that al-Sadr's supporters may escalate their protests, pushing the conflict-ravaged country into a new phase of instability.

see,es/sri (AFP, AP, dpa, Reuters)