"They've got a little more than two weeks to come aboard the Demobilisation and Social Reintegration programme and we hope they'll get the message because the deadline is April 1," William Swing said in a statement broadcast on Okapi radio, a station set up with UN partnership for a vast country emerging from war.

Since the conflict that ravaged whole tracts of the DRC between 1998 and 2003 and drew in the armies of half a dozen other African nations, Ituri on the border with Uganda has remained a hotbed of ethnic and political strife.

Six militia armies are active there, battling each other and terrorising and carrying out atrocities against civilians, according to MONUC observers and rights groups. A voluntary disarmament scheme launched in September last year has so far won over fewer than 4,000 of an estimated 15,000 fighters.

Asked about hardline UN military ground operations backed by air power against the militias since late last month, the special representative of the UN secretary general was "to give a signal to the militias".

Swing's broadcast was recorded Sunday when he was on a brief trip to Bunia, the main town in the region, to inspect the situation after UN forces from four countries carried out a security sweep last week following an earlier attack against a militia group that on February 25 murdered nine Bangladeshi soldiers in an ambush.

In the first operation, about 60 militiamen were killed and their base in a market town was destroyed, according to UN military sources. Townspeople have claimed that several civilians were also killed, a charge denied by MONUC, but the mission has launched an enquiry.

Swing said it was up to the militias, drawn mainly either from the majority Lendu ethnic community or their minority Hema rivals, to disarm "immediately ... (but MONUC) will continue to talk to them and convince them this programme is the only way out."

"This April 1 date is the deadline for the process as envisaged when it was launched," MONUC spokesman Mamadou Bah said on Monday.

Bah gave no details of what the UN force, now some 16,700 strong across a country headed by President Joseph Kabila's transitional government including former rebels, would do after that date if the militias failed to comply.

On March 6, the UN peacekeepers launched a disarmament programme aimed at collecting weapons from almost 4,000 members of a group known as the Armed Forces of the Congolese People based at Aru in the north of Ituri.

These fighters collectively agreed to turn in their weapons and the national disarmament commission is cooperating with MONUC to set up a transit camp for them at Aru, where they will receive training ahead of being reintegrated into civilian life or being taken into the armed forces.

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