Two explosives planted in the streets of the northern city of Mosul detonated near US patrols, according to witnesses, who said they didn't think there were any casualties.
One blast near a Mosul school caused panicked children to rush out of the building before lessons were cancelled for the day, said Khairy Ilham, a shopkeeper who witnessed the blast.
In Baghdad, fighters opened fire on a two-tonne army truck transporting Iraqi soldiers in an eastern neighbourhood. The truck overturned, injuring 12 troop members, police Maj. Musa Hussain said.
Aljazeera learned that a car bomb exploded on Thursday as a joint US-Iraqi patrol was passing by in the Abu Ghraib neighbourhood west of Baghdad.
The blast set a US Humvee ablaze.
Also Thursday in Rabia, 150 km west of Mosul, Iraqi police mistook a group of security forces dressed in civilian clothing for attackers and opened fire, killing two police and three soldiers, according to the region's police chief, Ahmad Muhammad Khalaf.
Witnesses said there were no US
casualties in the Mosul attack
Eight other police were injured in the resulting gunfight, which lasted about 10 minutes.
In Falluja, police imposed a sudden, late-afternoon curfew in parts of the city, shouting through loudspeakers: "Close your stores and go home!"
They also set up checkpoints and searched cars in the city.
The curfew may have been related to a battle that broke out earlier in the northern Jolan neighbourhood between fighters and Iraqi security forces.
"We were surprised to see a large number of Iraqi security forces raiding homes and dragging out young men, maybe for investigations," said Jamal Muhammad, a resident.
The US military on Thursday announced that a prisoner died a day earlier at the Camp Charlie internment facility.
Schroeder was urged to
intervene for captive's release
The man, in his early 30s, was found lying down in his cell on Wednesday, four days after his arrival at Camp Charlie, the military said in a statement.
Attempts to revive him failed, and the cause of death was under investigation.
Iraqi fighters have seized an Iraqi with German citizenship and demanded in a videotape message that Germany release Muslim prisoners.
Iraqi captors holding a man they say has a German passport have called on Germany to release Muslims imprisoned in its jails, Aljazeera said on Thursday.
The group calling itself Protectors of Islam Brigades is holding Abd al-Hussain al-Zaidi, who in the video called on the German government, Chancellor Gerhard Schroeder and German media to quickly intervene for his release," Aljazeera said, showing a video of al-Zaidi and two masked fighters behind him.
Aljazeera said it obtained the videotape from The Associated Press.