In Baghdad, rescuers lifted blackened corpses from the ruins of a Christmas Eve suicide truck bombing that killed eight people, further unnerving Iraq's embattled Christian community as they celebrated the birth of Christ.

Five Iraqis, including a woman, were killed and another five wounded when a makeshift bomb exploded on a road frequented by US convoys in the volatile bastion of Samarra, said police.

To the south, three Iraqis were killed in another deadly bombing between Najaf and Karbala, a week after twin attacks killed 66 people in the two holy Shiite Muslim cities.

A doctor at a clinic in Khan al-Nus, north of Najaf, said three Iraqis died and two were wounded when a car bomb exploded in the path of a US military convoy, which escaped unscathed.

The Najaf police chief has accused Damascus of being behind last Sunday's bombing, charging that a suspect "confessed that Syrian intelligence services had played a role".

In a clutch of targeted assassinations, an Iraqi working as an interpreter for the US military and his wife were shot dead by gunmen near the northern city of Mosul -- their bodies riddled with 30 bullet holes, said police.

Haidar al-Mussawi, a member of the Iraqi National Congress political party, said the blast happened about 300 metres away from his home.

"A fire ball shot into the sky and blew out the windows of my house."

At Yarmuk hospital Saturday morning, the wounded, ranging from tiny girls to middle-aged men, lay in hospital beds, some with third degree burns, their faces puffed out black and their arms dangling listlessly.

Relatives hovered over the moaning and sleeping victims in a barren, grey hospital room.

The bloodshed put Christians, already jittery, on a knife's edge as they feared the possibility of a Christmas Day attack.

Coordinated bombings of five churches in Mosul and Baghdad in August killing 10 people sent notice to the dwindling community of 700,000 they were being targeted by insurgents.

Supressing their fears, some 80 Christians had braved the streets to attend an early Christmas Eve mass Friday.

"Despite the threats, my husband and I have come. I will not let the terrorists intimidate me and make me shirk my religious duties," said Maha, a 50-year-old lawyer, at the heavily guarded Church of the Assumption of the Virgin Mary.

Meanwhile, US Defense Secretary Donald Rumsfeld visiting US troops in Iraq Friday painted a bleak picture of Iraq ahead of the much anticipated January 30 elections but vowed America would prevail over a tenacious insurgency.

"All along the way, it is bumpy and it's tough... It is not a smooth, easy path to success, there are setbacks," Rumsfeld told troops at Camp Fallujah outside the rebel stronghold recaptured by the military last month.

"But you will look back when you are about my age and you will be proud."

Rumsfeld has been lambasted at home over the revelation that he did not personally sign condolence letters to relatives of troops killed in Iraq and over his perceived indifference to the shortage of armour for US military vehicles.

Rumsfeld's first stop was in the main northern city of Mosul, where a suicide attack on a US army base killed 22 people on Tuesday. The attack has resulted in a top-to-bottom review of base security in Iraq.

Brigadier General Richard Formica, who previously probed the abuse of detainees in Iraq, has been appointed to investigate the attack, Lieutenant Colonel Paul Hastings told AFP.

The US military announced it had arrested 34 people and thwarted a car bombing in Mosul in the aftermath of the deadliest attack ever on Americans in Iraq.

Back in Fallujah, fighting erupted for Friday for a second straight day as residents sought to return home after last month's massive US-led assault to restore government control over the city which had been under rebel control since April.

Many of those who ventured in said they would not stay in a "ghost city."

Amid sounds of fighting, a number of the 25 cars lined up at a checkpoint decided to leave rather than return to the war zone they had fled ahead of the offensive to reclaim the city of 300,000.