At least 12 people have been killed and 25 others hurt in a suicide bomb attack in a market in the south of Baghdad, the Iraqi capital, security officials have said.
The attacker targeted a US military patrol travelling through the market in the district of Dora on Thursday, officials from the Iraqi interior and defence ministries said.
An Iraqi police source said three US soldiers were among those killed in the blast, but the US military said it was awaiting further details.
"Right now, we have an initial report of an attack in the area, and a unit is en route to the location," a US military statement said.
The attack comes days after 10 people were killed and 37 hurt when a vehicle blew up in a wholesale produce market in Dora.
Dora, a confessionally mixed district, has been one of the Iraqi capital's most dangerous areas.
Another explosion also occurred inside a Baghdad police station on Thursday, killing three policemen and injuring 20 people, including 12 officers and eight civilians.
The bomb had been left in a rubbish bin in the police station.
Kirkuk attack
A third attack - a suicide bombing - took place on Thursday killing eight people and injuring seven others in the northern city of Kirkuk, an Iraqi police official said.
The attacker targeted a military base where members of the local Awakening Council had gathered to collect salaries, Major Salam Zankana said.
The Awakening Council is a paramilitary group made up of Sunni Muslims opposed to an al-Qaeda-led battle against the Iraqi government and the presence of foreign troops in the country.
"While we were waiting at a gate talking to one another a big explosion took place," Sami Ghayashi, one of those hurt in the blast, said.
"I saw several colleagues dead, among them my cousin. I have no idea how this suicide bomber got among us."
Also on Thursday, three policemen were killed when a bomb was detonated inside a police station in western Baghdad, another Iraqi police official said, on condition of anonymity.
At least 19 people were wounded in the attack, he said.