The U.S. military says eight American soldiers have been killed in fighting in Iraq since Tuesday - six in Baghdad, and two in the northern province of Salahuddin.
The military says in one incident, two soldiers were killed and another wounded Wednesday while engaged in an operation to "capture and detain targeted insurgents" in eastern Baghdad.
In other violence, Iraqi authorities say a bomb blast early Wednesday in Baghdad's Sadr City district killed at least 11 people and wounded about 20 others.
Sadr City is a largely Shi'ite district that is a stronghold of the Mahdi Army militia, loyal to radical cleric Moqtada al-Sadr.
In other developments, the U.S. military says Iraqi soldiers captured a key financier of al-Qaida in Iraq and his associate during an operation in the northern city of Mosul.
The military also says troops killed an al-Qaida in Iraq leader and detained 18 suspected terrorists during operations in central and northern Iraq.
A separate statement says U.S. troops captured a person in Karbala linked to the al-Quds Force of the Iranian Revolutionary Guards Corps. U.S. officials have accused Iran of supporting Shi'ite militias in Iraq.
Meanwhile, the United Nations says Secretary-General Ban Ki-moon plans to appoint veteran European diplomat Staffan de Mistura as the top U.N. envoy in Iraq. The 60-year-old Swedish and Italian national will succeed Pakistani envoy Ashraf Qazi, who has been assigned to lead U.N. operations in Sudan.
Some information for this report was provided by AFP, AP and Reuters.