Three aid workers, including a US woman and two Sudanese nationals, have been kidnapped in Sudan's troubled Darfur region, officials say.

三名救援人员——一名美国妇女和两名苏丹侨民，在苏丹达尔富尔地区被绑架。

The victims were stopped by an armed gang near the town of Nyala, capital of South Darfur state, government minister Abdelbagi Gailani told the BBC.

He said the kidnappers¹ made off with（逃跑，偷走） the group's two vehicles, and that they were probably being held for ransom²（赎金） .

This is the latest in a series of kidnappings of aid workers in Darfur.

Last month, four South Africans from the African Union peacekeeping mission were kidnapped in Nyala. They were later released.

The US embassy has confirmed the abduction（绑架，诱拐） of the American aid worker, and said it was working with its contacts to follow the situation closely.

In the early stages of the Darfur civil war, it was unusual for foreign nationals to be targeted, says the BBC's James Copnall in the capital Khartoum.

But ever since President Omar al-Bashir was indicted³ last year by the International Criminal Court for war crimes allegedly committed in Darfur, the situation for humanitarian⁴（人道主义的，博爱的） workers has greatly deteriorated⁵, he adds.

A succession of foreigners has been abducted⁶, with the kidnappers usually demanding a ransom.

Fresh fighting

In a separate development, a major rebel group, the Justice and Equality Movement (Jem), has released 44 prisoners.

The men, soldiers from the Sudanese Armed Forces, were handed over to the International Committee of the Red Cross (ICRC).

There has been an upsurge（高涨） of fighting in Darfur in recent weeks, the area as a whole remains⁷ very insecure, and the peace process is shaky, our correspondent says.

The Sudanese army has taken over control of an area that used to be Jem's stronghold（要塞） , Jebel Marra.

Rebel movements in Darfur have been fighting government soldiers and Arab militias⁸（国民军，义勇军） , backed by Khartoum.

About 300,000 people have died since fighting began in 2003, and some 2.7 million people have fled their homes as a result of the conflict.