The EU's aid chief said the violence in Sudan's Darfur region had worsened since the government and rebels signed new security agreements two weeks ago.
On the eve of a visit to Sudan, EU Development and Humanitarian Aid Commissioner Louis Michel on Thursday echoed US and UN criticism of rebels for an upsurge of violence this week in Tawilla town in North Darfur state.
"Two weeks ago, all parties agreed to cease hostilities, which are exacting an unacceptable toll on human life," he said in a statement issued in Brussels.
"Not only has this ceasefire not been respected, but the situation has deteriorated to such an extent that aid workers have also been forced to flee the region," he said, referring to attacks around Tawilla.
Rebels abandoned Tawilla on Wednesday after two days of heavy fighting that followed several weeks of skirmishing between Arab militias and African rebels. Rebels say the government launched air strikes on Tadit, a village south of the North Darfur capital El Fasher.
The UN has condemned the fighting, which comes two weeks after the government and the rebels signed a security protocol in the Nigerian capital Abuja on Nov. 9.
Meanwhile, the chief UN envoy for Sudan, Jan Pronk, said on Thursday that the rebel Sudan Liberation Army is to blame for the renewed fighting that has cut deliveries of food to 300,000 people in north Darfur.
"This was a unilateral violation of the agreements by SLA, not by the government," Pronk told reporters of the fighting that broke out last week.
It is rare that the UN lays the blame squarely on one party to a conflict in which it is playing a humanitarian role.
The SLA has rejected it is responsible for the renewed fighting, telling Al-Jazeera television on Thursday it was responding to attacks by the state air force and pro-government militia.
The World Food Program says the battle in north Darfur has forced it to suspend deliveries of food to about 300,000 displaced people in camps in the area.
Plonk, who had flown to Cairo for talks with the Egyptian government and the Arab League, called on the world to double the peacekeeping force assigned to Darfur and to put pressure on the Sudanese government and the southern rebels, the Sudan People's Liberation Army, to meet their Dec. 31 deadline for a permanent settlement to the rebellion in southern Sudan.
The African Union force of ceasefire monitors and troops in Darfur is currently being increased to about 4,000 personnel. Pronk declined to suggest a figure for AU troops, but he called for a force large enough to provide "protection by presence" in all of Darfur's hotspots.
``You cannot do that with 4,000. I would argue: `Let's try twice as many. The problem is twice as big as many people think,''' he said.