Muhammad Hamza al-Zubaydi, who played a key role in the brutal suppression of the Shiite Muslim uprising of 1991, was arrested Monday in Iraq, the U.S. Central Command said.

Al-Zubaydi, a former member of the Iraqi Revolutionary Command Council and central Euphrates regional commander, was No. 18 on a list of the 55 most-wanted figures from Saddam Hussein's regime.

Central Command have no details on his arrest, but Abu Dhabi television reported that al-Zubaydi was arrested by Iraqi National Congress forces in Hillah, about 55 miles south of Baghdad, and turned him over to U.S. forces.

Haidar Ahmad of the Iraqi National Congress in London said "free Iraqi forces" affiliated with the congress captured him.

Al-Zubaydi, a former prime minister and deputy prime minister, stood among Saddam's henchmen for his role in squelching the Shiite uprising that followed Iraq's defeat in the 1991 Gulf War. He was featured in an Iraqi news film kicking and beating captured Shiite rebels.

He was the queen of spades in the deck of former Iraqi officials distributed to U.S. forces.

With Monday's capture, eight of the most-wanted members of Saddam's inner circle are now in custody, though none of them are from the very top of the list. A ninth figure, Ali "Chemical Ali" Hassan al-Majid -- a top adviser to Saddam -- is believed to have been killed in a coalition airstrike in Basra.

Saddam Hussein's son-in-law, Jamal Mustafa Abdallah Sultan al-Tikriti, and one of the toppled Iraqi leader's bodyguards also surrendered to Iraqi National Congress forces, the group said Sunday.

Other top arrests by coalition forces include Watban and Barzan Ibrahim Hasan al-Tikriti, two of Saddam's three half brothers; Hikmat Mizban Ibrahim al-Azzawi, the finance minister and deputy prime minister; science adviser Lt. Gen. Amer al-Saadi; Samir Abd al-Aziz al-Najim, a senior figure in Saddam's Baath Party, and Abd al-Khaliq Abd al-Gafar, minister of scientific research and higher education.