A group of 29 Chinese workers taken by rebels in southern Sudan 11 days ago has been freed in good health and flown to Kenya, officials said on Tuesday, after Beijing protested their capture.

"The Sudanese authorities allowed a Red Cross plane to take them from Kauda to Nairobi ... this Tuesday morning where they were given to the Chinese embassy there," the foreign ministry said.

The Kauda area in the Nuba Mountains of South Kordofan state has been the scene of fighting since June between government troops and rebels formerly aligned with the rulers of now independent South Sudan.

The International Committee of the Red Cross (ICRC) confirmed it arranged the transport of the 29 Chinese, who were released by rebels of the Sudan People's Liberation Movement-North (SPLM-N).

China last week lodged a formal protest with Khartoum over the workers' capture and dispatched a six-member team to help gain their freedom.

Vice Foreign Minister Xie Hangsheng summoned a top-level Sudanese embassy diplomat and urged the African nation to "do everything it can to ensure the safety of the Chinese personnel," the ministry's website said.

China's foreign ministry confirmed late Tuesday that the workers had arrived in the Kenyan capital, the official Xinhua news agency reported.

"The 29 persons are currently in sound physical conditions and stable mood," the ministry said in a statement quoted by Xinhua.

It added the workers were handed over to the Chinese embassy after they landed in Nairobi, where they appeared flanked by ambassador to Kenya Liu Guangyuan and Qiu Xuejun, head of the team sent to help secure their release.

They were due to head home after a short stay in Nairobi, Xinhua said.

Rebel spokesman Arnu Ngutulu Lodi told AFP he would comment later Tuesday, but the release comes a day after he said he expected the 29 Chinese workers to be released "very soon."

Lodi said on Monday the rebels were in communication with the Chinese government.

The captives, who were involved in a road-building project in South Kordofan, had been held since January 28 when the SPLM-N destroyed a Sudanese military convoy between Rashad town and Al-Abbasiya and took over the area, the rebels said.

ICRC said it was not involved in negotiations to free the Chinese.

The SPLM-N maintained that all 29 Chinese were safe during their captivity.

According to Xinhua the workers were taken after a rebel attack on their camp.

Sudan's foreign ministry spokesman Al-Obeid Meruh said that in addition to the 29 freed Chinese, 17 others had earlier been "released" by the Sudan Armed Forces but one other Chinese died.

"His body was found yesterday," Meruh said.

Xinhua reported on Monday that Beijing had been informed by Sudanese authorities that the body of a Chinese, who went missing in the attack, had been found.

Chinese embassy officials in Khartoum could not be reached on Tuesday.

Last week, SPLM-N chairman Malik Agar met a Chinese diplomat and asked Beijing to use its influence with Khartoum to help badly needed aid to reach the war zone, Lodi said.

Agar held the talks in Addis Ababa with the Chinese ambassador to Ethiopia.

China is Sudan's major trading partner, the largest buyer of Sudanese oil and a key military supplier to the Khartoum regime.

Sudan has severely restricted the work of foreign relief agencies in South Kordofan and nearby Blue Nile state, where a similar war began in September.

About 30,000 people fled when the rebels took control of villages in the Al-Abbasiya area on January 28, the United Nations said.

The UN has backed statements by the United States that there could be a famine unless urgent aid is allowed to enter South Kordofan and Blue Nile.