A car bomb has exploded in central Baghdad, killing at least nine people and wounding more than 23 others, security officials said.
The bomb on Thursday went off in al-Sinaa street in the central Karrada neighbourhood, they said, adding that the blast happened at around 9:30am (06:30 GMT) as a US military patrol passed through the area.
Iraqi police said one US soldier was killed in the attack but the US military did not confirmed the casualty. A US armoured vehicle was also damaged.
It comes amid fierce fighting in the Iraqi capital's Sadr City between Shia fighters and Iraqi security forces backed by US troops.
Civilian casualties
Overnight clashes in Sadr City left another eight people killed, including two children, officials said.
According to data collected by the interior, health and defence ministries and made available to AFP news agency, 966 civilians were killed across Iraq in April, as were 69 police officers and 38 soldiers.
A security official said most of the fatalities were in clashes between troops and militia loyal to Muqtada al-Sadr, the anti-American Shia leader based in Sadr City, a sprawling Baghdad district of some two million people.
The fighting between security forces and Shia fighters erupted in the southern city of Basra on March 25, and spread quickly to other Shia areas of Iraq, particularly Sadr City.