The EU executive's department for African development has warned the bloc's governments that such a deployment could give cover for a larger military operation against the Islamists who control Mogadishu.

The stark warning given to envoys of the 25 EU states said a peacekeeping operation without the consent of all sides would be seen as an "invading force" and exacerbate the risk of conflict and of jihadist attacks, the sources said.

A U.N. Security Council committee is considering what action to take after receiving a report last week finding extensive illegal arms flows into Somalia, both to the Islamic Courts Union movement and to the shaky interim government.

Commission sources said U.S. officials had drafted a document calling for a partial lifting of the arms embargo and the deployment of a regional peacekeeping force.

One EU official, speaking on condition of anonymity, said some member states shared Brussels' misgivings but Security Council permanent members Britain and France were reluctant to oppose Washington openly because of the "terrorism issue".

European Commission experts are also concerned the EU could come under pressure to fund a regional force through its Africa Peace Facility. The African Union has requested 15 million euros ($19.22 million) for the mission.

A U.S. State Department spokesman was not immediately available for comment.

U.S. officials have said the Bush administration is looking at a range of ideas for Somalia, possibly including a regional force. Washington has made clear in recent weeks that neighbouring countries such as Ethiopia and Eritrea should not be allowed to interfere in Somali affairs.

EU ambassadors discussed Somalia on Tuesday after receiving the warning report from the executive European Commission.

"The majority of countries broadly backed the Commission line," said one envoy, adding there would be further discussions in coming days.

BLANK CHEQUE?

The United States has accused the Islamic Courts, in the ascendancy in the lawless East African country, of harbouring al Qaeda operatives and warned that neighbouring Kenya and Ethiopia could be targets of "extremist elements" from Somalia.

The Brussels experts argue that sending a regional security force could give a blank cheque for neighbouring countries to intervene in Somalia and legitimise an Ethiopian military presence which is denied by Addis Ababa.

It would undermine EU-backed attempts to reach a political settlement in Somalia through dialogue and play into the hands of Ethiopian-backed Somali leaders seeking a military confrontation, they say.

They say the United States is already providing Ethiopia and Kenya with logistical support and U.S. special forces had been observed on the Kenya-Somalia border.

They argue that any "peace support" operation could act as a cover for a much broader military operation against the Islamic Courts, or give the Islamists a pretext to launch a pre-emptive attack on Baidoa, seat of the provisional Somali government.

More widely, it could exacerbate conflict between Ethiopia and Eritrea, accused of arming the Islamic Courts, and draw in Sudan, making it harder for the international community to stop violence against civilians in the Sudanese region of Darfur.