Iraqi Shia radical leader Moqtada al-Sadr said yesterday that he has suspended indefinitely the activity of his feared 60,000 strong militia, the Mahdi Army.
"The Mahdi Army suspension will be valid indefinitely and anyone who does not follow this order will not be considered a member of this group," said a statement issued by Sadr in the Shia shrine city of Najaf.
"We have set a cultural programme for the Madhi Army and we have named it Al-Mumahidun (Supporters of the Mahdi), and everybody should abide by it and whoever does not agree with it will be expelled from the army."
There was no immediate explanation for Sadr's decision which came after he promised earlier this month to dismantle the once feared militia if a planned security pact between Baghdad and Washington provides for the withdrawal of US troops.
The two sides are still negotiating the planned pact that would govern US troop levels and allow them to operate after a UN mandate expires at the end of the year.
Iraqi Prime Minister Nuri al-Maliki said this week that they had agreed there would be no foreign forces in Iraq after 2011, setting a timeline for a US withdrawal.
Maliki stressed however that despite the progress, there were still points of disagreement crucial to both sides in the proposed security pact.
The White House has repeatedly echoed that no deal has been finalised.
Sadr ordered a six-month freeze in attacks on rival armed groups and US forces in August last year after allegations that his fighters had been involved in bloody clashes with security forces in the shrine city of Karbala.
The decision came at the same time many Sunni rebel groups in western Iraq decided to join forces with the US military to fight al-Qaeda and amid a "surge" in American troop numbers.
Sadr extended the freeze for a further six months in February.
The Iraqi prime minister ordered an offensive against militias in the second city of Basra in late March, which sparked fighting between the security forces and Mahdi Army fighters in Shia areas across central and southern Iraq.
Hundreds were killed in street battles in the Baghdad Shia district of Sadr City, which ended only with the signing of a truce on May 10.
Sadr forces have also clashed with other Shia factions, notably the Supreme Iraqi Islamic Council (SIIC) a Shia religious party led by Abdel Aziz al-Hakim, a key government ally of the prime minister.
Currently believed to be in Iran, Sadr led two uprisings against US-led coalition forces in 2004 and had repeatedly vowed to fight on until US troops leave.