At least 10 African Union soldiers have been killed and 50 are reported missing after a weekend assault on their base in southern Darfur.
It was the worst attack yet on AU peacekeepers in the war-torn Sudanese region since their deployment three years ago, and happened just weeks before the first wave of new UN troops is set to arrive.
"Our camp has been completely destroyed," an AU spokesman, Noureddine Mezni, said yesterday. "There is a feeling of shock."
As many as 1,000 armed men in at least 30 vehicles stormed the base in Haskanita, South Darfur just after sunset on Saturday evening in what the AU called a "deliberate and sustained" assault.
The latest violence to threaten Darfur's fragile peace process came as a new diplomatic initiative for ending the four-year conflict got under way.
Brought together by former South African president Nelson Mandela, the so-called "peace elders" include his wife and rights activist Graca Machel, South African archbishop Desmond Tutu, former US president Jimmy Carter, the former UN envoy to Iraq Lakhdar Brahimi as well as the British business tycoon Richard Branson. They arrived in Sudan yesterday and are due to meet Sudan's president Omar al-Bashir, before continuing on to Darfur to talk to community leaders.
Following the attack on the AU base, both the Sudanese government and rebel leaders pinned the blame on each other. However, the AU force commander, Martin Luther Agwai, appeared to suggest responsibility for the attack lay with one of Darfur's numerous rebel movements when he commented that "rebel groups, who indulge in such random violence and bloodshed, undermine their own credibility on any negotiation table".
Peace talks between Khartoum and the rebel movements are due to begin later this month, hosted by Muammar Gaddafi in the Libyan capital, Tripoli.
Sources in Sudan suggested the attack may have been carried out by a renegade rebel commander keen to establish his own group. Since the last Darfur peace agreement was signed in May 2006 the number of rebel groups has grown from three to at least 15.
The 7,000 AU troops have been unable to quell the violence and a 26,000-strong joint UN/AU force is set to replace the ailing AU force over the coming months, with the first troops expected in the region by the end of October.
The weekend assault on the Haskanita base, which happened just after the fast-breaking meal during the Muslim holy month of Ramadan, served to illustrate the importance of reinforcements.
Egypt's Foreign Minister, Ahmed Aboul Gheit, said the attack "confirms the need to send the African and UN hybrid force (to Darfur) as soon as possible". But Khartoum has blocked its deployment at almost every step, throwing up logistical obstacles and repeatedly going back on promises.
As the negotiations continue, conditions on the ground are deteriorating. Since 2003, more than 200,000 people have died and 2.5 million have been driven from their homes.
A UN assessment report released in September concluded that the humanitarian situation in Darfur became even worse in August. Around 100 aid workers had been taken hostage and nearly 100 vehicles hijacked this year. Oxfam last week warned it may be forced to pull out of Darfur due to the increasing violence.