At least 23 Iraqis were killed and 60 wounded in Monday's attacks as the US ambassador called on Iraqi politicians to agree upon a government of national unity.
A US soldier was 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 said.
Earlier, 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 police officer.
Black plastic bag
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.
Labourers were waiting for work
when the blast occurred
"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.
At least three shop fronts were blown out and several cars destroyed.
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."
Zalmay Khalilzad, the US ambassador, accused Iran on Monday of providing training and weapons to Iraqi militias and extremist groups and criticised Tehran's demand that British forces immediately withdraw from the southern city of Basra.
He said that while Iraq and Iran maintained good relations, "Iran has another policy as well, which is to work with the militias and extremist groups and provide training and weapons, direct or indirect."
He said there was evidence of "at least indirect help" by Iran to unidentified Shia politicians.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.
On Friday, Iranian Foreign Minister Manushehr Mottaki called for British troops to withdraw from Basra, accusing them of destabilising Iraq's second-largest city.
"Basra is Iraqi territory when I last checked the map," Khalilzad said. "I think that was uncalled for interference by Iran...I think their role taken a more negative turn with this statement."
Five people were killed in the
Mosul restaurant blast
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 police officers working in Mosul, 360km northwest of Baghdad.
Two kidnapped Macedonian contractors were released on Monday in 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 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 ransom from their employers. It was unknown whether any ransom had been paid.