Humanitarian workers in eastern Chad have reported an increase in the number of refugees fleeing the Darfur region of western Sudan after weeks of relative quiet.
They said cross-border raids by pro-government Janjawid militias were increasing again and expressed fears that the Sudanese government was trying to prevent many more refugees from crossing the border.
The sources said on Monday that the UN refugee agency UNHCR had registered some 420 new arrivals in the area around the Chadian town of Birak over the weekend. These people had spilled across the border in small groups over the past two weeks, they added.
"It does represent a significant change from what we've seen before," one UN worker told IRIN by telephone from Abeche, the main town in eastern Chad. "For the two months before that, the numbers crossing the border had really been negligible."
The registration tally of new refugees in Birak was expected to top 500, the official said, confirming a report by a BBC correspondent on the spot that about 500 people had crossed the border there recently.
Nearly 200,000 refugees from Darfur have fled into Chad since the fighting in western Sudan hotted up at the end of last year.
Humanitarian agencies would have to wait and see whether the new trickle would develop into a substantial influx, the UN official said, citing reports which indicated that the Sudanese authorities were trying to prevent more people from escaping.
"We believe the Sudanese government are doing everything they can to stop them crossing over the border with Chad," the UN official said. "An important new wave of refugees would be a very clear signal that the violence is continuing."
The Sudanese government has been widely accused of using the Janjawid, an Arab militia mounted on horses and camels, to attack black African farmers in Darfur and drive them from their villages. Many refugees have reported that Janjawid raids were often preceded by attacks by Sudanese military aircraft.
Khartoum is halfway through the 30-day period set by the UN Security Council for it to take concrete steps to disarm the Janjawid and restore security in Darfur. The council passed a resolution on 30 July threatening punitive measures, including possible economic sanctions, if the Sudanese government failed to comply.
The United Nations has described Darfur as the worst humanitarian crisis in the world and estimates 2.2 million of the region's six million inhabitants are in urgent need of food and medicine.
The refugees who arrived in Birak in early August included some people who had escaped to Chad, but who had gone back to Sudan in the hope that there would soon be peace following the declaration of a ceasefire by the government and two rebel groups in April.
Humanitarian workers said that these people had now completely lost faith in the peace process and fear had forced them to run away and seek sanctuary in Chad for a second time.
"The attacks are obviously continuing," the UN official said. "And there have been incursions by the Janjawid into the Birak region over the last few days. The atmosphere along the border is tense."
Some 400 horsemen were sighted in the area on Friday and there were reports of four male refugees being killed in nearby Senette, the official said.
Earlier this month, France sent 200 of its troops stationed in Chad to help government's own security forces patrol the Sudanese border and prevent further Janjawid incursions.
This article was produced by IRIN News while it was part of the United Nations Office for the Coordination of Humanitarian Affairs. Please send queries on copyright or liability to the UN. For more information: https://shop.un.org/rights-permissions