Darfur's rebel Sudan Liberation Army (SLA) has denied any involvement in the kidnapping of Irish aid worker Sharon Commins and a colleague yesterday.
The group, which is active in some areas surrounding Kutum where the kidnapping took place, blamed government-backed militias for the incident.
Aid groups in Darfur say they have faced increased hostility since March, when the International Criminal Court (ICC) issued an arrest warrant for Sudan's president Omar Hassan al-Bashir to face charges of masterminding war crimes in the region. Sudan's government has accused some aid workers of working as spies for Western governments and Khartoum expelled 13 humanitarian groups after the ICC's decision, accusing them of helping the Hague-based court build up its case.
But Sudan's ministry of foreign affairs today dismissed the accusation, saying authorities were doing all they could to locate the kidnappers. "The government of Sudan has nothing to gain from these activities," said Ali Youssef Ahmed, head of protocol at the ministry.
"The government is following the case closely. It is trying to identify the kidnappers, their whereabouts and what demands they have. The government is keen to secure a safe resolution."
Two groups of foreign aid workers kidnapped in Darfur in March and April were released unharmed. UN agencies and aid groups are running the world's largest humanitarian operation on Darfur, helping 4.7 million caught up in more than six years of fighting.
Violence surged when mostly non-Arab rebels took up arms against Sudan's government in 2003, accusing it of marginalising the region. Khartoum mobilised troops and mostly Arab militias to crush the rebellion.
Estimates of the resulting death toll range from 10,000, according to Khartoum, to 300,000 according to United Nations humanitarian chief John Holmes.