The political movement of Iraqi cleric and militia leader Moqtada al-Sadr said it would end a two-month boycott of parliament yesterday, smoothing over a rift with its Shi?ite allies in the US-backed government.

The political reconciliation with a group viewed with suspicion in Washington came the day after US forces suffered one of their costliest days in Iraq. A total of 19 soldiers were killed, including 12 on a helicopter and five in a clash in a Shi?ite holy city that the US military blamed on militiamen.

Shi?ite Prime Minister Nuri al-Maliki has been under pressure to crack down on the Mehdi Army, a militia loyal to Sadr that the United States sees as the biggest threat to security in Iraq. But his past dependence on Sadr?s political support has made that difficult.

The Sadrists announced a boycott late last year to press their demand for a timetable for the withdrawal of US troops from Iraq and to protest against a meeting between Maliki and President Bush.

?We are ending our boycott of the ministries and the parliament,? Bahaa al-Araji, a senior member of the Sadrist group, told a news conference with the ruling Shi?ite Alliance, adding that there had been a response to their demands.

The US military yesterday revised the number killed in Saturday?s Blackhawk helicopter crash from 13 to 12. It said another five soldiers were killed and three wounded in the clash at a government building in Kerbala. It was unclear whether the helicopter was shot down. Residents near Baquba in violent Diyala province northeast of Baghdad said they saw a helicopter in flames in the air.

Two other soldiers were killed elsewhere on Saturday and the deaths of two killed on Friday were also announced.

<B>Resistance from opposition Democrats</B>

It was the deadliest day for US forces since Bush announced he was sending about 20,000 more troops to Iraq to try to prevent sectarian civil war between Shi?ite Muslims and the once-dominant Sunni Arab minority.

His plans have run into resistance from opposition Democrats who now control Congress and skepticism in Washington about how far Maliki can make good on promises to disarm Shi?ite militias.

The US military said yesterday a brigade of around 3,200 soldiers had arrived in Baghdad, the first of some 17,000 planned reinforcements for the city, and it would be fully operational by the start of February.

The Kerbala clash came as thousands of pilgrims thronged to the city 110 km south of Baghdad at the start of the 10-day rite of Ashura, a highpoint of the Shi?ite calendar and a previous target for attacks by al Qaeda and other Sunnis.

?The Provincial Joint Coordination Center in Kerbala was attacked with grenades, small arms and indirect fire by an illegally armed militia group,? the US military said in a statement, apparently blaming Shi?ite militiamen rather than Sunni insurgents to whom it usually refers as ?terrorists?. ?Five US soldiers were killed and three wounded while repelling the attack,? it said without mentioning attackers killed or detained.

US officials did not immediately explain how the assailants? identity was established. ?We do know they?re militiamen but we?re not going to go any further than that,? Maj. Steven Lamb said, adding investigations were continuing.

An Iraqi local government official who said he was in the building that came under attack questioned the identification of those who fought the US troops just after dark. Relations have become strained between Washington and the Iraqi government as the United States presses Baghdad to rein in Shi?ite militias blamed for death squad killings and tries to limit the influence of neighboring Shi?ite Iran.

Maliki vowed this month to crack down on both Shi?ite and Sunni gunmen in a major US-backed operation. Sadr enjoys a mass following in Iraq and some backing from Iran.

Parliamentary speaker Mahmoud al-Mashhadani said all parliamentary parties would form a committee to discuss the reasons for the Sadrists? boycott and resolve the issues. ?This is a new beginning,? he told the news conference. ?We want to say to the world that an Iraqi solution for Iraqi problems is the key, and others must support these solutions.?

In fresh violence yesterday, a roadside bomb killed one British soldier and wounded four in the southern city of Basra, the British military said.

<B>Aseel KAMI</B>