By Khalid Abdelaziz

KHARTOUM (Reuters) - A 72-year-old Swiss aid worker was freed by security forces early on Wednesday more than a month after she was abducted in Sudan's Darfur region, officials said.

Margaret Schenkel later flew back to the capital Khartoum, but did not give details of her ordeal to waiting journalists.

She was kidnapped on Oct. 7 in the main city in North Darfur region, El Fasher, a hub for relief workers and U.N./African Union peacekeepers.

Security forces launched an operation to free her from a rural area where she was being held outside the southern town of Kutum, a spokesman for the regional government said.

The leader and one member of the six-man kidnapping gang had been arrested, Sudan's foreign ministry spokesman, Qarib al-Khidr, said.

Neither Switzerland nor Sudan paid a ransom, he added.

Khartoum has been at war with rebel groups in Darfur since 2003, but much of the conflict has descended into banditry and gangs have kidnapped people for ransom.

The Swiss foreign ministry thanked Sudan for its help in freeing Schenkel. Officials have not named her aid group.

(Reporting by Kahlid Abdelaziz; Additional reporting by John Miller in Zurich; Writing by Eric Knecht and Nadine Awadalla; Editing by Raissa Kasolowsky and Andrew Heavens)