Radical Iraqi cleric Moqtada Sadr has told his militia to leave the southern city of Najaf, the scene of frequent clashes with US-led forces in the past.
Sadr has been reining in his militiamen in recent weeks
Mr Sadr issued a statement calling on his men who are not from Najaf to "do their duty" and go home.
He agreed a truce earlier - although isolated outbreaks of fighting between militia and police continued in Najaf.
Last week the cleric announced he would set up a political party to contest elections next year.
Under the truce agreed with US-led forces on 4 June, Mr Sadr had told his Mehdi Army militiamen to stop attacking coalition troops and withdraw from Najaf and nearby Kufa.
US forces pulled out to their base on the edge of the city, while Iraqi police moved in.
However violence flared up again in Najaf last week.
At least six Iraqis died in clashes between the Mehdi Army and Iraqi police.
The BBC's Dumeetha Luthra in Baghdad says that Mr Sadr's latest order for his men to leave Najaf appears to be a tentative step to secure a place in a future Iraqi government.
During Friday prayers last week, he urged supporters not attack Iraqi security forces, and said the recently formed interim government was a opportunity to "build a unified Iraq".
Interim Iraqi President Ghazi Yawer has said Mr Sadr can join the political process if he disbands his militia.
Mr Sadr's call comes a day after US President George W Bush said it was up to the Iraqi authorities to deal with him.
The cleric launched an uprising in April, after the US-led occupation authorities closed his newspaper, arrested a key aide and called for his arrest over the killing of a moderate Shia leader.