At least 10 people have been killed and more than 45 others wounded in a suicide car bombing targeting a police patrol in the northern Iraqi city of Mosul.
Six policemen and four civilians were killed in the blast on Monday, which went off near the main police station in the Dawasa district in the city's central area.
Mosul, Iraq's third largest city, is regarded by the US military as the last urban bastion of al-Qaeda in Iraq.
In an earlier separate attack in the city, a university professor was blown up in his car as he drove home on Monday evening.
Faris Younis, who taught in the agriculture department of the University of Mosul, was killed when a bomb planted in his car exploded, local police officials said.
Iraqi security forces backed by the US military launched a major crackdown against in the city on May 14.
Over 1,300 people have been detained since then.
Baghdad blast
In violence elsewhere in Iraq, a civilian man was killed in a roadside bomb blast in Baghdad's Bab al-Muadham neighbourhood, police said.
At least six other people were wounded in the blast, according to the police.
A pro-government fighter and a police officer were killed in confrontations near the city of Baquba, a security official said.
Meanwhile, the US military released a statement saying that US troops killed two people and captured 31 others in two days of operations against al-Qaeda in Iraq.
The two deaths occurred northwest of Tikrit when US soldiers returned fire and called in air support after coming under fire from "multiple enemy positions", according to the statement.
The battle took place early on Monday in a remote area about 160km north of Baghdad, it said.
US troops later found a car containing bomb-making materials and a tunnel system leading to a sleeping area and weapons storage facility, the statement said.
Also on Monday, Iraqi security forces arrested Munadhal Abdul Karim, a leader from the Soldiers of Heaven cult, in a coffee shop in central Basra, according to Major-general Mohammed Jawad Huwaidi, a commander of military operations in Basra.