Baghdad, Iraq (CNN) -- Bomb attacks killed at least 18 people, including two U.S. soldiers, and wounded more at least 55 others in Iraq in the past two days, officials said.
A suicide car bomb targeting a U.S. military patrol exploded in a busy outdoor market in Iraq's Diyala province around 8:30 a.m. Friday (1:30 a.m. ET), killing two U.S. soldiers and wounding six others, military officials said. The blast also killed six Iraqis and wounded 22 others, Iraqi police officials told CNN.
An hour later, a roadside bomb exploded in an outdoor market in the predominately Sunni al-Dora district in southern Baghdad, killing three people and wounding 10 others, police officials in Baghdad said.
The attacks come as Iraq is facing political uncertainty. Three months after the country's national elections, it has yet to form a government, a process described by Western officials as lagging and expected to take months.
Shiite and Sunni imams urged the politicians to speed up the process Friday.
At least three people were killed and 13 others wounded when a parked car bomb detonated in the city of Tikrit Thursday.
According to police, the car was parked near a bakery and detonated shortly before midnight.
Such late-night bombings are rare in Iraq. Tikrit is a predominantly Sunni city north of Baghdad in Salaheddin Province.
On Thursday evening, at least four people were killed and 10 others wounded in a suicide car bombing in Baghdad, an Interior Ministry official said.
According to the official, the bomber struck a joint security checkpoint outside the predominantly Sunni district of Ameriya in the western part of the capital.
He said among those killed was a local Sons of Iraq (SOI) leader, who officials believe was the target of the attack. Those killed and wounded include Iraqi police, army and SOI, he said.
Sons of Iraq are mainly made up of Sunni Arab fighters who turned on al-Qaeda and are credited for being one of the main factors that contributed to the drop in violence across the country in the past two years.
SOI members and leaders have been a frequent target of al-Qaeda in Iraq.
Overall violence in Iraq has dropped drastically over the past two years compared to the height of the sectarian war in 2006 and 2007, but bombing attacks have continued.