A car bomb exploded in a small market near a police station in Tikrit, killing at least 31 people and wounding 70, a police officer said.
Police Lieutenant-Colonel Saad Daham said when security forces prevented the attacker from exploding the vehicle in front of the station in Saddam Hussein's hometown on Wednesday, he swerved into a crowd of people at the nearby market.
It was 7.15am (0315 GMT), and many day labourers who had travelled to Tikrit from poorer areas of Iraq were waiting at the market to be picked up for work at local construction sites, Daham said.
At Tikrit general hospital, Dr Faisal Mahmud said the facility was too small to handle so many casualties.
Tikrit, 130km north of Baghdad, has been the scene of growing unrest since the US-led invasion of Iraq more than two years ago.
Also on Wednesday, a
man with explosives hidden under his clothes set them off while standing in a line of job applicants waiting outside a police and army recruitment centre in northern Iraq, killing 30 people and wounding 35, police said.
Police first thought the powerful blast in Hawija, a small town 240km north of Baghdad, was caused by a car bomb, but police Major Sarhad Qadir later said they found it was an attacker waiting in a line of about 150 recruits.
"I was standing near the centre and all of a sudden it turned into a scene of dead bodies and pools of blood"
"I was standing near the centre and all of a sudden it turned into a scene of dead bodies and pools of blood," said police Sergeant Khalaf Abbas. "Windows were blown out in nearby houses, leaving the street covered by glass."
Qadir said 30 people were killed and 35 were wounded, including about 15 who were in critical condition.
Like many other such recruitment centres in Iraq, Hawija's is located in a building surrounded by cement walls topped with barbed wire in an effort to prevent attacks by car bombs.
Iraqi journalist Walid Khalid told Aljazeera an Iraqi police checkpoint in al-Arbaa Shawaraa intersection in al-Yarmuk neighbourhood west of Baghdad was attacked by a car bomb.
The blast killed four Iraqis, including two policemen, and wounded nine. Four civilian cars and two police vehicles were set ablaze.
Two more car bombs were detonated in Baghdad, one of which targeted a police station in the southern district of Dura, killing three people, an Interior Ministry official.
Many of the wounded were taken
to al-Yarmuk hospital
Khalid reported the charred bodies were those of two female students and a driver.
The blast also wounded eight Iraqis, including two policemen, he added.
Aljazeera learned that two civilians were wounded in a second car bomb explosion in the Baghdad al-Jadida neighbourhood in the southeast of the capital.
In al-Jamia neighbourhood west of Baghdad, an improvised explosive device targeting a US patrol exploded and wounded seven garbage collectors who were taken to al-Yarmuk hospital.
In al-Ghazaliya district, west of Baghdad, armed fighters carrying machine guns attacked an Iraqi police checkpoint, killing a policeman and wounding another who was transferred to al-Shuala hospital.