World Bulletin/News Desk

Chief mediator of the African Union High-Level Implementation Panel on Sudan Thabo Mbeki on Sunday asked Sudanese authorities to let him meet chief of the opposition National Umma Party al-Sadig al-Mahdi who was arrested Saturday for "damaging the reputation" of state security agencies.

"Mbeki expressed concerns at al-Mahdi's detention and the effect of this move on dialogue in Sudan," al-Mahdi's daughter Mariam, also the head of communication at the Umma Party, told reporters following a meeting with the former South African president.

"He told us that he had requested a meeting with al-Mahdi and that he waits for the Sudanese government to respond," she added.

Commissioned to settle internal Sudanese disputes and also conflicts between Sudan and South Sudan, Mbeki met on Saturday with a host of Sudanese opposition leaders in Khartoum.

Umma Party said late Saturday that it would withdraw from a national dialogue suggested by the ruling Sudanese National Congress Party, led by President Omar al-Bashir, because of the arrest of its leader.

Al-Mahdi, Sudan's prime minister between 1966 and 1967 and again between 1986 and 1989, was detained by Sudan's national intelligence agency late on Saturday at his home in the Sudanese city of Omdurman, his party said.

He was taken to an unknown place, according to al-Mahdi's secretary, Mohamed Zaki.

His party said that the arrest came in connection with al-Mahdi's criticism of the country's security agencies and blaming them for violence in the troubled Darfur region.

Sudan has been plagued by internal differences, fights between the army and rebel movements, especially in the southern and western parts of the country, and a deteriorating economy.

What initially seemed to be a popular uprising against long-time president al-Bashir in some of the country's states last year was immediately and brutally quashed by the authorities.

Al-Bashir called for national dialogue with the nation's opposition in January this year within the context of a wider reform plan.

In early April, the Sudanese president gathered the opposition in Khartoum and pledged broader freedoms for the country's political forces.

He also promised the release of all political detainees who had not been convicted of criminal offences.