Bombers and gunmen killed more than 54 people in a wave of attacks around Iraq as armed men pursued their campaign against the security forces of the embattled coalition government.

In the bloodiest incident, a massive roadside bomb ripped apart a bus carrying Iraqi soldiers from Baghdad to the northern city of Mosul, killing at least 23 and wounding 20 more, military headquarters said.

This attack followed a blast in the centre of Baghdad, where a bomber rammed his explosives-packed car into a crowd of police and soldiers outside a bank, killing at least 10 of them and four bystanders.

Shortly afterwards, another bomber blew up a vehicle in Palestine Street in the east of the city, wounding one member of the security forces, police said.

Four electricity board employees were killed and four more wounded when their minibus was sprayed with gunfire in central Baghdad.

A car bomb also exploded in the violently divided city of Muqdadiyah, 100 kilometres (60 miles) northeast of Baghdad, killing seven people and wounding 10, police said.

Another bomber killed three Iraqi soldiers at a checkpoint in the northern town of Tall Afar, a military source said.

In Kirkuk -- an ethnically northern mixed city and a centre of the oil industry -- two policemen were killed and two more, including a senior officer, were wounded in a roadside bombing, police said.

Two coalition soldiers -- one British and one American -- were also killed, their respective headquarters said.

The attacks came after Prime Minister Nuri al-Maliki's embattled government vowed last week to rid Iraq of the "terrorists" who have brought bloodshed to its streets since US-led troops ousted        Saddam Hussein's regime in 2003.

In Tikrit, Lieutenant Colonel Rabae Al-Kidawi told AFP the army bus was hit about 20 kilometres (13 miles) north of the city, Saddam's hometown.

"The soldiers were travelling from Baghdad to Mosul on the highway to take up their duty there," he said. Iraq's military headquarters put the toll at 23 dead and 20 wounded.

In Baghdad, troops had arrived at the al-Rafidein bank to collect their wages when the bomber struck, witnesses told AFP at the scene.

Medics at the nearby Ibn al-Nafis Hospital said they had received 10 dead soldiers and 25 wounded.

The Kindi Hospital, which is better equipped for trauma victims, was treating nine wounded soldiers and six civilians, a medic there said.

A defence ministry official confirmed that there had been military casualties, although he could not say how many, and added that four civilians were also known to have died.

The bank bomber struck in the Karrada district, not far from rubble left by a car bombing and a series of mortar strikes that killed 31 people Thursday.

Karrada was once seen as relatively peaceful, where Baghdadis from all the city's confessional and ethnic groups would do their shopping while violence raged in other districts.

It is still one of the rare places in Baghdad to be completely under Iraqi control, with no US military oversight or joint patrols.

In a separate attack in Kirkuk, Sheik Abdul Razak al-Ibadi, a 55-year-old tribal leader among the area's Shiite minority, was shot dead outside his home.

In the south of the country, a British soldier was killed when a mortar round crashed into his base camp in Basra in the early hours of the morning, the defence ministry said in London.

On Monday, a US soldier was killed and another wounded when their supply convoy was hit by a roadside bomb, coalition headquarters said.

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