The U.S. military says coalition forces have killed one al-Qaida-in-Iraq terrorist and detained eight suspects during operations in Baghdad and northern and central Iraq, Friday.

The military also announced the deaths of two American soldiers. It said both soldiers died Thursday. One was killed in combat in Diyala province and the other died in a non-combat related incident in the city of Kirkuk.

In southern Iraq, police say gunmen shot dead a top aide to the country's most respected Shi'ite cleric, Grand Ayatollah Ali al-Sistani. Police say the aide, Sheikh Amjad al-Jinabi, and his driver were traveling west of Basra, when gunmen attacked their vehicle late Thursday.

Also on Thursday, U.S. forces detained an Iranian man in the Iraqi town of Sulaimaniya on suspicion of smuggling roadside bombs and foreign terrorists into Iraq.

The military says the man belongs to the Quds force of Iran's Revolutionary Guards.

Iran says the man was part of a business delegation from Iran's Kermanshah province.

The U.S. Defense Department says U.S. forces have detained a total of seven Iranian Quds force operatives in Iraq.

In another development, the deputy commander of U.S. forces in Iraq, Lieutenant General Raymond Odierno, says that attacks in Iraq have fallen in recent months.

U.S. forces began a security crackdown in Baghdad in February, and later expanded it to other provinces.