KHARTOUM, Sudan — Three Russian aircrew members kidnapped in Darfur over the weekend were released Tuesday after a military operation by Sudan's army, officials said.

The three, who were working for the Sudanese Badr Airlines but subcontracted to the UN-African Union peacekeeping mission, were taken Sunday on their way back from the market inside the region's largest town, Nyala.

"South Darfur's governor announces the release of the abducted Russian pilots," the Sudanese Media Center said.

Badr Airlines deputy head Mutaz Shora said the three were in the care of the South Darfur authorities in Nyala.

"I am told they are in good health," he said.

State Minister of Humanitarian Affairs Mutrif Siddig said the three were released by a military operation similar to one that freed two kidnapped Jordanian peacekeepers earlier this month.

"Now there are no more hostages in Darfur, and the authorities will be taking the necessary measures [to stop this]," he said. He gave no further details.

Kidnapping mostly by young men from Arab tribes demanding ransom began last year after the International Criminal Court issued an arrest warrant for Sudanese President Omar Hassan al-Bashir for war crimes and crimes against humanity.

Bashir denies the charges and responded by expelling 13 aid agencies working in Darfur to help some 4 million people affected by the seven-year revolt.

More than 20 foreign aid workers and peacekeepers have been abducted since last year. All have been released.

Khartoum has failed to arrest any of the kidnappers, and reports of ransoms being paid have fueled abductions. Khartoum denies paying any ransom money.

The International Criminal Court added genocide to Bashir's charges this year, and since then at least eight aid workers have been expelled from Darfur.