Updated

Saddam Hussein's half brother was nabbed by U.S. special forces Thursday as coalition troops continued to track down key members of the deposed Iraqi regime.

One American commander said Barzan Ibrahim Hasan had "extensive knowledge" of the toppled regime's inner workings as an advisor of Saddam and former head of Iraqi intelligence.

Another one of Saddam's half brothers, Watban Ibrahim Hasan, was nabbed Sunday, while the third — Sab'awi Ibrahim Hasan — reportedly has fled to Syria.

All three are wanted by the coalition for various war and humanitarian crimes, including rape, torture and using brutal force to repress uprisings against the Iraqi regime after the 1991 Gulf War.

Barzan was the five of clubs in the deck of 55 playing cards the U.S. military issued to troops with pictures of wanted Iraqi officials last week.

The deck includes what is left of the so-called "dirty dozen" — the name the Bush administration gave Saddam and his closest officials in the fall of 2002 as it prepared prosecutions for chemical attacks, forced deportations, mass killings, torture, and other alleged crimes against humanity.

During a U.S. Central Command briefing Thursday, Brig. Gen. Vincent Brooks said Barzan was captured alone in Baghdad with the help of U.S. Marines and tips from Iraqi residents.

The U.S.-led coalition is "relentlessly pursuing the scattered members of a fractured regime," Brooks said. Attacks against those leaders were continuing.

"We are currently asking a number of questions ... finding out whatever we can from this capture," Brooks said.

Barzan, the youngest of Saddam's half brothers at age 53, ran the Iraqi intelligence service, the Mukhabarat, from 1979 to 1983 and was Iraq's ambassador to the United Nations in Geneva from 1988 to 1997. As head of the Mukhabarat, he expanded Iraq's terror machine, carrying out dozens of operations overseas against Iraqi dissidents.

Barzan may be charged with the disappearance and execution of several thousand Kurds, as well as murders and assassinations abroad.

His home west of Baghdad was targeted by six U.S. "smart bombs" last week. Some news reports said Barzan was killed in that bombing.

According to Agence France-Presse, a family friend said Saddam placed Barzan under house arrest on March 5 in a presidential palace in Jadriya, near Baghdad airport, for refusing to promise support to Saddam's younger son Qusay in the event of Saddam's death.

When U.S. troops entered Baghdad on April 9, Barzan is thought to have fled to his home in the Ramadi district.

Barzan was Saddam's favorite half brother and was only 18 when he took part in the 1968 coup that brought the Baath party to power. But his unruly behavior, tendency to drink and constant womanizing had Saddam seeing red.

Disputes arose between Barzan and Saddam in 1983 when Barzan was in his intelligence role, according to Globalsecurity.org. All three half brothers were demoted from their positions.

But Barzan was rehabilitated when Saddam made him Iraq's representative to the United Nations in Geneva in 1988.

While in Geneva, Barzan was also responsible for the regime's finances abroad. He was part of the Iraqi delegation that met U.S. Secretary of State James Baker in Geneva in January 1991 in a last effort to head off the first Gulf War. He wasn't well received in Geneva's large diplomatic community.

Barzan is believed to have been vital to Saddam's secret acquisition of nuclear and military technology while in Geneva.

He fell from grace again in late 1998 after apparently claiming he would succeed Saddam as leader of Iraq, according to Globalsecurity.org.  Barzan was recalled home and interrogated by Qusay.

In 1999, Saddam's family accused Barzan of plotting to overthrow the regime, and he fled the country but later returned.

According to the Britain-based INDICT, a group established in 1996 to campaign for the creation of a tribunal to try the Iraqi regime on charges of war crimes and crimes against humanity, Barzan participated in the detention and murder of several thousand male members of the rebellious Barzani clan in 1983.

While head of the Mukhabarat, INDICT claims Barzan was responsible for the repression of religious and ethnic minorities including forced deportations, disappearances and murder. He also supervised the murder of at least six members of the al-Hakim clan, prominent worldwide among Shiites, and was involved in the arrest of 90 of its members.

Barzan also ordered the assassinations of Iraqi dissidents carried out on foreign soil by Mukhabarat agents, INDICT says, and carried out the destruction of the villages of Dujail and Jezan al-Chol in 1983, and the subsequent murder or deportation of residents there.

The eldest of Saddam's three half brothers, Watban Ibrahim Hasan, was caught in a raid on Sunday by U.S. special forces.

Watban's first senior position in government was as chief of the Amnal-An, or internal security department, in the late 1980s. Saddam then appointed him head of the Estikhabarat or military intelligence. He was named interior minister in 1991.

Watban, the five of spades on the deck of cards, was directly involved with brutal repression of Shiite Muslim uprisings in numerous Baghdad suburbs. He reportedly was involved in violent repression of religious and ethnic minorities and encouraged the use of torture and rape.

Saddam dismissed Watban as interior minister in 1995, but retained him as a presidential adviser. Some reports say Saddam always kept one wary eye on Watban.

INDICT also says Watban committed and encouraged regularly used torture, rape and the threat of rape by forces under his control.

Both men are likely to have information about Iraq's presumed program to manufacture weapons of mass destruction. Coalition forces thus far have not found any certain evidence that those weapons still exist in Iraq.

The third half brother, Sab'awi Ibrahim Hasan, reportedly took refuge in Syria. Sab'awi is the six of diamonds in the 55-card deck.

He is a former director of intelligence and the General Security Directorate. Sab'awi was deputy chief of police in Iraq before Saddam demoted the brothers in 1983. He was appointed head of the Mukhabarat in 1989.

Under his direction, repression of uprising following the first Gulf War in 1991 included mass executions and torture.

As far as war crimes, INDICT says Sab'awi, while head of the Mukhabarat in Kuwait during the Iraqi occupation between August 1990 and March 1991, was responsible for violations of the Geneva Convention, including murder, torture, rape and deportation. He also reportedly was involved in suppressing the Shiite uprisings with mass executions and torture.

Sab'awi increased the range of the Mukhabarat until by 1990, the organization had a huge budget and more than 100,000 staff and informers all working to make sure Saddam stayed in power.

Washington has warned Syria not to harbor fugitives from the Saddam regime, and officials in Damascus have repeatedly denied doing so.

Syria in recent days twice turned away Abu Abbas, the leader of the Palestinian terrorist group that carried out the 1985 Achille Lauro cruise-ship hijacking, during which a disabled American retiree was shot dead. Abbas was caught in Baghdad Monday.

The Associated Press contributed to this report.