"We are concerned about Syria. We are anxious about the effort (to develop weapon of mass destruction) they have made in the past," Defence Secretary Geoff Hoon told a press briefing.

"We are anxious that they should not take advantage of any scientific or military figures crossing the border," he said, adding however: "It's important to maintain the dialogue with Syria at this stage."

Britain and the United States have been warning Syria for several days against giving safe haven to fleeing members of Saddam Hussein's regime.

But Hoon's remarks Monday -- just as Britain's minister for Middle East affairs Mike O'Brien was visiting Damascus -- reflected newfound concern that Syria might try to tap Iraqi weapons-making talent for its own ends.

Hoon said US and British forces remained "absolutely convinced" the weapons of mass destruction exist inside Iraq, but added that it could take some time to uncover them.

"The search is proceeding," he said.

"Obviously, as more areas are liberated, we are getting an increasing amount of information from the local people as to where they think those weapons might be hidden. Clearly those are being followed up."

But he added: "The most effective way of securing the weapons of mass destruction is by speaking to those from within the regime who have knowledge of their location and that obviously is now under way as significant leadership elements are surrendering or coming over and talking to us."

"Obviously it will take some time to fully analyse what they have to say but that work is under way," he said.

SPACE.WIRE