After Iraq warned that it would use unconventional means to try and retake the airport, Air Marshal Brian Burridge told BBC's Newsnight programme from Qatar: "It may be one of two things."

"An attack with chemical or biological weapons -- that would have very serious consequences for the regime in that it would be met with a proportional response and those responsible would be held to account," he said.

"Secondly, he could use a human tide and we had signs last night (Thursday) that there were loudspeakers in south-west Baghdad signalling people should rise up and march on the airport," he said.

"That was pretty much in character to use civilians in that way as human shields in a way that might put them in danger," he said.

Earlier Friday, Iraqi Information Minister Mohammad Said al-Sahhaf warned: "Tonight we will carry out something that is not conventional against them, not military. It will be a great example to them."

The US military said its troops seized control of the strategic prize of Baghdad's international airport on Friday and were flushing out remaining pockets of resistance.

Burridge said that while Saddam and his regime may want to "lash out in revenge" with biological and chemical weapons, their orders may not be followed.

"There has to be a command and control system to use such weapons and it may be some of those in it will be disinclined to carry out their orders because they know they will be held to account," he said.

The British commander said that the speed and tempo of the coalition's advance to the airport had caught the Iraqis off guard.

"There have been pockets of resistance and there continue to be at the airport, but nothing like what we expected. The Republican Guard just didn't show," he said.

He said that Saddam's regime did not have the option to adopt the Stalingrad approach in defending Baghdad, where Russian forces during World War II were able to leave the city and encircle the approaching enemy.

"When the regime crumbles that's going to have an effect on the population of Baghdad generally and the Baathist militias and paramilitaries and all the other thugs and death squads," he said.

"We will make sure we know what's going on, where the clusters of really bad people are and will deal with them bit by bit, very deliberately," he said.

"I'm talking about people who have lived above the law for 25 years. They have no ideology and they just know their own necks are on the line," he said.

SPACE.WIRE