"The hunting will continue," said US Lieutenant Colonel David Rababy, adding that the Americans would not give up the search for the elusive Saddam himself.

"Anybody wanted by the United Nations or the United States will be caught. Bosnia is a good example, we're still catching them years after the war finished."

Barzan was captured in Baghdad alone on Wednesday during a special forces operations with support from the marines.

On Friday, the US military announced that special forces also captured a top Baath Party official, Samir al-Aziz al-Najim, on Thursday night. He was listed as regional command chairman for east Baghdad of the ruling party.

US authorities are remaining tight-lipped about details surrounding Barzan's capture. However, he was seized after the arrest last Sunday of his brother and former interior minister, Watban Ibrahim Hasan.

Both, as well as Najim, were on a US list of 55 most-wanted people from the toppled regime, and both had members of their family inter-married with their leader's siblings although this did not stop falling-outs.

Barzan was placed under house arrest after objecting to Saddam's wishes that his youngest son Qussay eventually replace him as Iraq's leader. And his daughter refused to marry the president's eldest son, Uday.

Lieutenant Colonel Will Costantini said the military had scoured through thousands of tip-offs prior to the arrest of Barzan and more high-profile captures could now be expected.

General Vincent Brooks said after the capture that this kind of information had contributed significantly to the operation.

"It's tonnes and tonnes of information which says something about the security situation, in that people are comfortable in coming forward and freely giving out information," he said.

However, Talib Zangana of the Free Iraqi Forces, a group of US-based Iraqi expatriates deployed for the war, said he believed most of the leadership had fled to Syria before the war began.

He said deputy prime minister Tareq Aziz had initially remained behind to fool the world into believing the entire government had stayed in Baghdad and that Saddam could still deliver a blow to the US.

"It is a real mystery how they all disappeared in one night, unless of course they were not here in the first place," Zangana said.

"In my opinion they went to other Arab countries -- Syria -- before the war started and left one or two behind to pretend the full government was here and in full control," he said.

He noted that Barzan's brother Watban had been arrested at the border while attempting to flee into Syria. "That tells you they had the green light to go into Syria."

Zangana warned that Washington had to avoid what happened in Afghanistan where al-Qaeda chief Osama bin Laden and Taliban leader Mullah Mohammad Omar evaded capture after the Americans invaded.

"That was a real blow to the Americans and we can not allow that blow to happen here," he said.

Rababy and Constantini, the US lieutenant colonels, agreed that further arrests could prove time-consuming but eventually the list of most wanted would face justice.

"With the arrest of Barzan, the US military has proved it will hunt down the bad guy, and it will continue," Rababy added.

SPACE.WIRE