BAGHDAD-A U.S. warplane strafed a house in the southern city of Basra, killing eight civilians, including two women and a child, Iraqi police said Saturday.

The U.S. military had no immediate comment on the report, which came a day after the first American airstrikes were launched in Basra during a week-old offensive against militant followers of radical Shiite cleric Muqtada al-Sadr.

Seven other people were wounded when the plane fired on a house in Basra's Hananiyah neighbourhood overnight, a local policeman said on condition of anonymity because of security concerns.

It was not immediately possible to independently verify whether those killed were civilians or combatants.

While the Iraqi police officer claimed it was a U.S. plane, British jets also have been providing air support in the area; it couldn't be immediately confirmed whether the plane was British or American.

The British military had no immediate information but said it also was looking into the reports.

"We are aware of reports of incidents in the Basra area resulting in civilian casualties," said Maj. Tom Holloway, a British military spokesman. "We are investigating those reports and do not have any further details at this time."

AP Television News footage showed smoke rising from Hananiyah. Pools of blood and a destroyed pickup truck were seen outside the home hit by the plane.

American support in Basra came as Iraqi troops struggled against strong resistance in the city, the nation's commercial centre and headquarters of the vital oil industry. Clashes there have sparked retaliatory fights in Baghdad and other Shiite cities.

U.S. military intelligence analysis of the fighting in Basra indicated Iraqi security forces controlled less than a quarter of the city, CNN reported on Saturday, citing unnamed officials in the U.S. and Iraq. The analysis also said militia members have deeply infiltrated Basra's police units.

The fight for Basra is crucial for the government of Iraqi Prime Minister Nouri al-Maliki, who is staking his credibility on gaining control of the city, Iraq's second largest, which has essentially been held by armed groups for nearly three years. Al-Maliki flew to Basra earlier this week to personally assume command of the operation and has vowed there would be "no retreat."

The crackdown in Basra has provoked a violent reaction - especially from al-Sadr's Mahdi Army. His followers accuse rival Shiite parties in the government of trying to crush their movement before provincial elections this fall.

Their anger has led to a sharp increase in attacks against American troops in Shiite areas following months of relative calm after al-Sadr declared a unilateral cease-fire last August and recently extended it for six months.

In extracts of an interview broadcast by the Al-Jazeera television network, al-Sadr called Saturday for Arab leaders to voice their support for Iraq's "resistance" to what he calls foreign occupation.

Many Shiite militias, including the Mahdi Army, are believed to receive weapons, money and training from nearby Iran, the world's most populous Shiite nation.

The situation in Basra remained tense as a Friday deadline for gunmen to surrender their weapons and renounce violence expired, although a few complied. Al-Maliki's office announced a new deal, offering Basra residents unspecified monetary compensation if they turn over "heavy and medium-size weapons" by April 8.

In Baghdad, Iraqi police said U.S. helicopters carried out airstrikes on the Shiite neighbourhood of Sadr City Friday night. Television footage showed destroyed buildings and the smoking wreckage of at least one car.

The U.S. military said in an e-mail that the only air assault it carried out last night was in the Kazamiyah neighbourhood, west of Sadr City, killing 10 militants.

Iraq's Health Ministry, which is close to the Sadrist movement, on Saturday reported at least 75 civilians have been killed and at least 500 others injured in a week of clashes and airstrikes in Sadr City and other eastern Baghdad neighborhoods.

The U.S. military sharply disputes the claims, having said that most of those killed were militia members.

Some 40 policemen in Sadr City handed over their weapons to al-Sadr's local office, one of the policemen told The Associated Press on Saturday.

"We can't fight our brothers in the Mahdi Army, so we came here to submit our weapons," the policeman said on condition of anonymity for security reasons.

The police in Sadr City have long been believed heavily influenced or infiltrated by Mahdi militiamen.

AP Television News footage showed a group of about a dozen uniformed police, their faces covered with masks to shield their identity, being met by Sheik Salman al-Feraiji, al-Sadr's chief representative in Sadr City.

Al-Feraiji greeted each policeman and gave them a copy of the Quran and an olive branch as they handed over their guns and ammunition.

Meanwhile, mortar or rockets were again lobbed on Saturday from Shiite areas in eastern Baghdad toward the Green Zone, the fortified area where the U.S. and British embassies are located, along with much of the Iraqi government.

The U.S. military said in an e-mail they "have no reports of serious injuries" following the incoming rounds.

Mortars also landed in Shiite areas of eastern Baghdad, killing at least one person and injuring 12, according to police. It was not clear from where the mortars were fired.
© 2008 Associated Press