A bomber strapped with explosives has blown himself up on a bus in central Baghdad killing at least 12 people, while explosions elsewhere in Iraq have killed at least another eight people.

A total of at least 23 Iraqis were killed and 60 wounded in Monday's multiple attacks against the backdrop of a call by the US ambassador to Iraqi politicians to agree upon a government of national unity.

A US soldier was also killed and three wounded in a roadside bomb attack south of Karbala, in southern Iraq, bringing the toll for US military deaths in Iraq to 2278 since the March 2003 invasion, according to an AFP count based on Pentagon figures.

The attack on the bus in the mostly Shia Muslim al-Kadhimiya district on Monday wounded at least nine people, sources added.

Earlier during the day, an explosion occured shortly before 8am near Liberation Square in al-Bab al-Sharqi area in Baghdad where a group of men were waiting near stands serving tea and sandwiches.

Lieutenant Ali Mutib said the blast killed at least four workers and wounded 14 other people, including one policeman.

Husain Muhammad Naama, who sells snacks and drinks to such workers, said a man bought a cup of tea and left a black plastic bag near his street stand.

"He drank his tea and left the bag near the stand. I went to a nearby restaurant to get water and then the bag exploded," Naama said.

"We don't know what to do; we need a solution. We can't live like this."

At least three shop fronts were blown out and several cars destroyed.

Workers swept up shattered glass and pools of blood that covered the street.

One worker, Said Isa, 28, said: "We want to live, but the government doesn't care about us. The Americans and the police are only protecting themselves while nobody protects us."

Impoverished Iraqi workers have been targeted previously. On 1 February, a bomb killed eight men waiting for day labour in a largely Shia area of Baghdad.

Envoy's warning

Zalmay Khalilzad, the US ambassador, warned at a news conference on Monday that polarisation along ethnic and sectarian lines was "the fundamental problem" in Iraq, adding that armed anti-government fighters were taking advantage of the upheaval.

On the same day that Khalilzad spoke, in Mosul a man with explosives concealed under his clothing entered a restaurant at about 7.30am and blew himself up among people eating breakfast, according to Captain Muhammad Khalil and hospital official Dr Ahmad Khalid.

Five people were killed and five others wounded, police and hospital sources said.

The blast devastated the Abu Ali restaurant, which is popular among Iraqi policemen working in Mosul, 360km northwest of Baghdad.

Blood and body parts were sprayed over the walls and floor, parts of the ceiling had collapsed and chairs and tables were obliterated by the force of the blast.

The owner, who identified himself only as Abu Ali, said: "Police were eating their breakfast and suddenly there was an explosion."

Macedonians freed

Two kidnapped Macedonian contractors were released on Monday in the southern city of Basra, a British official said.

The official, who spoke on condition of anonymity as he was unauthorised to comment to the media, declined to say
how the men were released or where they currently were.

The two men worked for a Macedonian cleaning company at Basra International Airport and were abducted on Thursday.

Their kidnappers demanded a 1 million US dollar ransom from their employers. It was unclear if any ransom had been paid.

PHOTO CAPTION

Iraqi policemen secure the scene of a roadside bomb attack along a highway in Baghdad, February 20, 2006. (REUTERS)