The World Food Program says three Bulgarian contractors kidnapped in Sudan's Darfur region have been freed after nearly five months in captivity.

The United Nations agency says the men appear to be in good health and will be flown to Sudan's capital, Khartoum, before traveling to Bulgaria.

In a statement Monday, WFP Regional Director Amer Daoudi thanked the Sudanese government for helping to secure the three men's release.

The men were working with the U.N. Humanitarian Air Service in Darfur when they were abducted by armed men on January 13.

The kidnapping took place at a landing strip about 60 kilometers southeast of the West Darfur state capital, El Geneina.

The agency says no ransom was paid to secure the Bulgarian crews' release.

Bandits and armed groups frequently kidnap U.N. and international aid workers in Darfur. The kidnappings have increased since March 2009, when the International Criminal Court indicted Sudanese President Omar al-Bashir for alleged war crimes in the region.

Most of the hostages have been released unharmed.

Darfur has experienced more than seven years of conflict since rebels took up arms against Mr. Bashir's government in 2003.