The journey is an arduous one -- it has to be made by road as there are no air links from Baghdad to the outside world, and hiring a car from the Iraqi capital for the 1,000 kilometres (600 miles) to the Jordanian capital Amman costs at least 1,000 dollars (920 euros).

Mohammed Latreche, president of the Party of Muslims in France, who organised the travel of some 30 human shields to Iraq, said that two of his volunteers are missing.

"All the others have returned, sometimes with difficulties, but we have not been able to make contact with these two volunteers who were in el-Rachida, an electric power station 15 kilometres north of Baghdad."

"I am also very worried for a young Parisian girl who we met in Baghdad. She arrived on her own at the start of February and in March, before I left, she said she had only 20 euros left.

"I don't know what has become of her," he added.

In the days before the United States unleashed its bombing campaign on Baghdad, it was estimated that between 200 and 275 human shields had taken up positions in Iraq, mainly on the outskirts of the capital.

The volunteers hoped their presence at certain specific installations in the country would deter the coalition from launching the war in the first place and also thwart the bombing of civilian targets such as power stations and water plants.

Ingrid, a young Swedish volunteer, said she left the Iraqi capital on Monday with a dozen companions and tried in vain to look for some fellow volunteers to warn them of their impending departure.

"We do not know where they are, it has been several days that we have been without news of some people," she said by telephone from Amman.

Carly Roberts, spokeswoman of the British-based Human Shield organisation, said there are some 60 human shields still in Baghdad and many of these are now trying to leave.

She said a "good twenty" should return in the weeks to come, while 40 want to stay to offer their help in rebuilding Iraq.

The volunteers appear to have been leaving Baghdad in disarray, in the absence of any organised plans to evacuate the human shields as a group.

The journey is best made in a convoy as roads out of Iraq are still not safe, but many former human shields have left the country either in small groups or completely alone.

"There is no centralisation for the mobilisation movement," said Natasha Quester-Semeon, a member of French group Les Humains Associes, which took part in the human shield project.

"Human shields are a utopian ideal which brings together willing people who have no other label or membership," she said.

But Jean-Michel Houpline, a 43-year-old Belgian, said the human shield movement has grown in size and become more structured during its activity in Iraq.

"We can be more efficient now," he said, raising the possibility that the human shield volunteers could now launch a pacifist action in Palestine.

SPACE.WIRE