NAIROBI, 1 September 2010 (IRIN) - Three Russian pilots released on 30 August, two days after they were kidnapped in Darfur, were only the latest in a string of foreigners associated with humanitarian operations there to be abducted this year.

The concern from the humanitarian side is that these kidnappings affect the ability of humanitarians to carry out their work in Darfur. The lack of arrests and prosecutions in any of these cases has frequently been cited as contributing to a climate of impunity, meaning that the threat would appear to remain undiminished, Samuel Hendricks, spokesman for OCHA in Sudan, told IRIN.

In all, some 22 aid workers, peacekeepers and pilots have been abducted at gunpoint, for periods ranging from three to 147 days (see table).

The trend led UN Secretary-General Ban Ki-moon to speak out earlier this month, saying: "Continued attacks on UNAMID [UN-AU Mission in Darfur] peacekeepers and abductions and mistreatment of UN staff and humanitarian workers will only aggravate the situation" in Darfur.

Humanitarian operations in the region have also been affected by the Sudanese government's expulsion of 13 international aid agencies in January 2009 following the arrest warrant for alleged crimes against humanity issued against President Omar al-Bashir.