The U.S. military says special Iraqi Army troops have detained a senior Health Ministry official accused of being a central figure in infiltrating Shi'ite militiamen into the ministry.
A military statement did not name the official, but said he is implicated in sectarian killings and funneling millions of dollars to the Mahdi Army of radical Shi'ite cleric Moqtada al-Sadr.
A Health Ministry spokesman named the detained official as Deputy Health Minister Hakim Zamili.
In the latest violence, Iraqi security officials say at least 35 people were killed in insurgent and sectarian attacks across the country, including a car bomb blast that killed at least 17 people, southeast of Baghdad.
The U.S. military says it killed 13 insurgents in an airstrike near Fallujah, west of Baghdad in al-Anbar province. The military also says four Marines were killed on Wednesday during fighting in Anbar.
The U.S. military is investigating Wednesday's crash of a Marine transport helicopter in Anbar province that killed all seven personnel aboard.
An al-Qaida-linked Sunni insurgent group says, in an Internet posting, that it shot down the helicopter.
U.S. Major General William Caldwell said Wednesday the Baghdad security crackdown currently under way will be expanded as more forces arrive. The plan calls for 90,000 Iraqi and American troops to operate in the city.
Some information for this report was provided by AP and Reuters.