Baghdad: A US airstrike targeted a building in Baghdad's Sadr City on Thursday, hours after American soldiers clashed with Shiite militants in fighting that left 15 people dead, police and the US military said.

The renewed violence coincided with the Congressional testimony of the Bush administration's top two officials in Iraq - General David Petraeus and Ambassador Ryan Crocker.

Petraeus recommended a pause in drawing down US troops in Iraq while the security situation remains unstable and US President George W. Bush is expected to follow his recommendation. But Prime Minister Nouri Al Maliki disagreed with Petraeus' proposal to delay further US troop withdrawals, citing the growing capabilities of Iraq's own security forces.

Petraeus wants the United States to complete by the end of July the withdrawal of the 20,000 troops that were sent to Iraq last year, leaving about 140,000 in the country.

More responsibilities

Beyond that, the general proposed a 45-day evaluation period to be followed by an indefinite period of assessment before any further pullouts.

Al Maliki, however, said he disagrees with that decision. "I believe the American forces can draw down," he told CNN on Sunday in an interview. "I don't believe the decision for a drawdown should be paused. ... The more US forces move back until all security responsibilities are handed over and coalition forces remain in a support role. And in a support role, you don't need such a big number." A senior government adviser said Al Maliki delivered that message to Bush in a 20-minute telephone conversation on Wednesday.

The Prime Minister told Bush that Iraqi security forces are capable of carrying out their duties and US troops should be pulled out as the situation permits, according to the adviser who sat in on the phone conversation.

He spoke on condition of anonymity because he was not authorised to disclose the confidential details.

Sadr City is a principal stronghold of the Mahdi Army militia of Shiite cleric Moqtada Al Sadr. Government troops supported by the US military have been fighting to gain control of the area for the past 10 days.

Casualties

A US military statement yesterday said 13 militants were killed in four separate clashes during the night. It also announced the death of another US soldier on Wednesday in a roadside bombing in Baghdad, raising to 18 the number of American troop deaths in Iraq since yesterday.

In one incident, the military said US helicopters fired two Hellfire missiles on gunmen attacking troops and setting up concrete barriers at a checkpoint. Four of the attackers were killed, a statement said. Police said the four killed were civilians, including two brothers who were under 10 years old.

Police also said two more men were killed yesterday morning when a US airstrike targeted a two-storey building in Sadr City with missiles after a number of oxygen cylinders were spotted on the sidewalk outside.

Yesterday morning, dozens of families squeezed through blast walls at the district's eastern entrance, carrying bags and pushing carts filled with clothes, groceries and other household items.

"We are fleeing because the shelling and airstrikes on us are increasing," said Nawal Abid, a housewife. The Baghdad military command announced that a two-week old vehicle ban in Sadr City would be lifted tomorrow.