(Adds details and background)
By Mariam Karouny and Tim Cocks
BAGHDAD, Feb 22 (Reuters) - Shi’ite cleric Moqtada al-Sadr extended his Mehdi Army militia’s ceasefire by six months on Friday, a decision U.S. officials said would help reconciliation among Iraq’s divided communities.
The renewal was welcomed by the Iraqi and U.S. governments, which say the initial six-month truce has helped reduce attacks on U.S. and Iraqi troops and the tit-for-tat sectarian violence that pushed Iraq to the brink of civil war.
In a statement, the U.S. military said it was ready for dialogue with Sadr’s movement, which opposes the American troop presence in Iraq. Sadr led his militia in two uprisings against U.S. forces in 2004.
White House spokesman Scott Stanzel said it was a positive step "to the extent that this will help reduce the violence".
Sadr’s decision could prove vital in determining whether security gains can be maintained, allowing the United States to continue withdrawing soldiers beyond the figure of more than 20,000 due to leave by July. There are about 155,000 U.S. soldiers in Iraq.
Several Mehdi Army members interviewed by Reuters expressed unhappiness with Sadr’s order, which they believed would expose them to attack by U.S. forces, but said they would obey.
"We knew there would be an extension of the freeze, but we thought it would be for a shorter period and we expected to be allowed to act in self-defence against U.S. forces. Now, after this statement, we can’t defend ourselves," said Amer al- Moussawi, a Mehdi Army member in the Shi’ite holy city of Najaf.
The U.S. military says the Mehdi Army contributed to sectarian violence with Iraq’s Sunni Arab minority in 2006 and 2007, and at one time called the militia the most serious threat to peace in the country, a description it now uses for al Qaeda.
The extension was announced two years to the day after suspected al Qaeda militants bombed a Shi’ite shrine in the town of Samarra, an event that led to a wave of revenge attacks on Sunni Arabs by the Mehdi Army.
"We have extended the freezing of activities of the Mehdi Army," said Asaad al-Naseri, a preacher at a mosque in the holy Shi’ite town of Kufa, reading a statement by Sadr.
Naseri said the renewal would last until mid-August.
A senior Sadrist said the reclusive cleric, who has rarely appeared in public in the past year, had renewed the truce so rogue members of the Mehdi Army could continue to be weeded out.
Deputy Prime Minister Barham Saleh praised Sadr’s move.
"I hope this suspension will culminate in the ultimate dissolution of armed groups," Saleh told Reuters by telephone.
The U.S. military said in a statement the truce extension would allow security forces to focus on combating al Qaeda.
"It will also foster a better opportunity for national reconciliation ... We also welcome an opportunity to participate in dialogue with the Sadr (movement) and all groups who seek to bring about reconciliation in building the new Iraq," it said.
Many Mehdi Army members and Sadrist political leaders wanted the truce to be scrapped, saying it was being exploited by Iraqi and U.S. forces to arrest Sadrists, especially in southern Iraq, where rival Shi’ite factions are vying for dominance.
Sadr called the truce after deadly clashes in late August between his militia, Iraqi forces and the Supreme Islamic Iraqi Council (SIIC), a rival Shi’ite faction, in the city of Kerbala.
Some analysts had said Sadr would be forced to renew the ceasefire given higher U.S. troop levels in Iraq, a move by some Sunni Arab insurgents to stop fighting and anger in Shi’ite areas at criminal activities by groups using the militia’s name.
"For the time being, the cost of declaring an all-out war on (SIIC) and the United States is far too high," Peter Harling, a Damascus-based analyst with the International Crisis Group think-tank, told Reuters by telephone. (Additional reporting by Ross Colvin and Wisam Mohammed in Baghdad and Khaled Farhan in Kufa; Writing by Dean Yates and Ross Colvin; Editing by Andrew Dobbie)