Insurgents blew up a small Shia mosque northeast of Baghdad yesterday, while police reported the discovery of nearly 40 bodies in several neighbourhoods of the Iraqi capital.

Ten Iraqis were killed in violence Sunday, while insurgents blew up a Shia mosque northeast of Baghdad as sectarian tensions festered in the country, still without a government nearly four months after a key national election.

The US military said the two pilots of the helicopter that crashed Saturday evening after coming under enemy fire were presumed dead.

"As reported earlier the aircraft was conducting a combat air patrol. Military officials believe the crash was the result of hostile fire," the military said in its statement.

The Apache Longbow helicopter went down Saturday at 5:30 pm (1330 GMT) southwest of Baghdad near Yussifiyah.

Earlier Sunday, an Iraqi insurgent group claimed responsibility for the attack in an unconfirmed statement published on the Internet.

The violence came as Secretary of State Condoleezza Rice and British Foreign Secretary Jack Straw made a surprise visit to press Iraqi politicians to speed up the formation of the government.

Rice arrived in Baghdad with Straw, a day after visiting his home region in northwest England.

The two were due to hold talks with Jaafari, who refuses to stand aside, and other leaders including President Jalal Talabani, a British official said. US officials make little secret of doubts about Jaafari's ability to unite and lead Iraq.

In Baqouba, 58km northeast of Baghdad, unidentified gunmen planted explosives around the small Guba Shia mosque and blew it up, police said. No casualties were reported. Three stores selling music CDs were also bombed.

A prominent Sunni lawmaker in Baghdad, meanwhile, reported that his brother disappeared last week in a possible kidnapping. Saleh al-Mutlaq said his brother, Taha, went missing while driving north out of Baghdad to Salahuddin province. Al-Mutlaq is the head of the Iraqi Front for National Dialogue party, to which his brother also belongs.

"We haven't heard any solid information about who could have been behind this operation," said al-Mutlaq, whose brother belongs to his political party. "I think this may be a political issue that has to do with my political activities."

The bodies found in Bagdad were all handcuffed and had been shot in the head or chest, said police Maj. Falah al-Mohammedawi. They apparently were victims of revenge killings between Sunni and Shia Muslims.

Also Sunday, six insurgents died while manufacturing a homemade bomb inside a house in Madain, about 14 miles southeast of Baghdad, police said.

Two American soldiers were killed by a roadside bomb while on patrol in central Baghdad late Saturday, the US military said.

Earlier Sunday the military said two other troops had died, a soldier near the oil-rich city of Kirkuk and a marine in the restive western province of Al Anbar.

The marine, assigned to the second brigade combat team stationed in Anbar province's turbulent capital, died from wounds sustained during combat on Friday.

The soldier, from the 101st Airborne Division, died from "non-battle related injuries" received in the course of an operation near Kirkuk on Thursday.

Elsewhere, the US military also said joint US-Iraqi troops killed four insurgents and wounded another Saturday after two failed attacks near Balad, 80km north of Baghdad.

Prime Minister Ibrahim al-Jaafari faced more pressure to step aside as the Shia bloc's nominee for a second term. Talks among Shia, Sunni and Kurdish leaders have stalled, in part because of opposition to al-Jaafari's nomination by the Shia bloc.

Shia legislator Jalal Eddin al-Sagheer was the latest to call for al-Jaafari to withdraw his nomination, saying the prime minister no longer had the acceptance of Iraqi parties and the international community.

"There is no other way out of the government formation problem," said Al-Sagheer, a member of the United Iraqi Alliance and of the Supreme Council for the Islamic Revolution in Iraq.

Further delays could "lead to more bloodshed," he added. On Saturday, Qassim Dawoud was the first Shia politician to join Sunnis and Kurds in publicly calling for a new Shia nominee. Shias politicians get first crack at the prime minister's job because they are the largest bloc in parliament.

US officials believe formation of a government of national unity would be a major step toward calming the insurgency and restoring order three years after the US-led invasion toppled Saddam Hussein. That would enable the US and its coalition partners to begin withdrawing troops.