A group of civilians abducted in Sudan's Darfur region on their way to a conference are still missing, the UN said on Wednesday, despite a rebel chief's order at least two days ago to free them.
Ali Al-Za'tari, the United Nations chief in Sudan, said he is "extremely concerned by the continued abduction of Sudanese civilians travelling from Zalingei in Central Darfur to Nyala, South Darfur, to attend a conference on internal displacement."
He called the abduction a serious crime.
The case highlighted security problems faced by 1.4 million Darfuris uprooted by the region's decade-old conflict, and whose future was under discussion at the conference which ended late on Tuesday.
Abdel Wahid Mohammed al-Nur, who heads a faction of the Sudan Liberation Army, told AFP on Monday night that his forces had seized the 31 internally displaced people in error.
"One of the commanders made a big mistake," he said. "I gave (an) order to release these people, civilians, immediately."
He could not be reached on Wednesday.
The African Union-UN peacekeeping mission in Darfur (UNAMID) said it was escorting the displaced people to the event when they were stopped "by a large unidentified armed group in military uniforms and seven jeep-mounted guns".