CNN reported that Syrian border guards were engaged during the incident Thursday, but Pentagon officials would not identify the injured Syrians or confirm if US forces clashed with Syrian forces on the border.

The attack aimed at suspected "leadership targets" in the convoy, which was heading toward Syria, officials said.

"There were a few Syrian nationals involved in the incident," said Lieutenant Colonel Gary Keck, a Pentagon spokesman. "A few may have been injured. We are treating those."

A US defense official who spoke on condition of anonymity said five Syrian nationals were injured, three of whom were treated for their injuries.

"It is still to be determined which side of the border" the convoy was on when it was hit, Keck said, adding that the United States was working with the Syrian government.

A defense official said 20 people were captured in the attack, but most of them were released after it was determined they were not a threat.

The attack has prompted reports that US officials believed deposed Iraqi leader Saddam Hussein or his sons may have been in the convoy.

US forces were investigating, but Keck could not say if any fugitive Iraqis were hit.

"We don't have specific details yet who was in the convoy or the number of enemy forces," a US defense official said.

"We do not have any confirmation of the identity of any individuals who might have been killed. Site exploitation continues, and routine DNA testing will be done if appropriate based on all intelligence gathering," the official said.

The White House would not say if Saddam or his sons were believed to have been in the convoy.

"I can confirm for you that there were military operations against leadership target or targets," White House spokesman Ari Fleischer told reporters.

"This should be seen in keeping with the ongoing military effort in Iraq to bring justice to people who we believe are associated with the regime or are leaders in the regime," added the spokesman.

A US defense official with knowledge of the intelligence that led to the strike, said reports that Saddam or his sons were hit were "wishful thinking."

The US defense official, who spoke on condition of anonymity, said he knew of no effort to collect DNA samples at the site.

"We attacked a convoy along a route. We thought it might have been leadership. We didn't know who," the official said.

Hopes of capturing the ousted Iraqi leader have risen since the detention one week ago of Saddam's closest aide, Abid Hamid Mahmud in northern Iraq.

Mahmud, number four on the US list of 55 most wanted Iraqis, has told his US captors that Saddam and his sons survived the war, the official confirmed.

Mahmud said he fled with them to Syria, but they were expelled following US pressure.

"That's what he said," said the official. "We don't know if it's true."

Saddam and his sons were the targets of at least two US air strikes during the war, but their fate is unknown.

The failure to account for them has given Iraq's former Baathists ruling party a rallying cry to resist the US occupation, US commanders and administration officials believe.

Near daily hit-and-run attacks have claimed mounting US casualties, prompting intensive US raids to crush the resistance before it can take root.

"I wouldn't underestimate the fear that Saddam still shadows his people with," King Abdullah II of Jordan told ABC television on Sunday. "There are a lot of Iraqis out there that think that he might still be alive, and might come back to haunt them."

But Abdullah played down the report that Saddam or his sons were killed in the attack.

"It's like Elvis. There's a lot of sightings of him all over the place," he said.

"You're getting so many stories, left, right, and center. But I've heard so many stories in the past several months," he said.

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