Early on Tuesday some of the almost 4,000 members of South Africa's ruling African National Congress (ANC) party began queuing to elect a party leader.

The contest between the rivals, President Thabo Mbeki and Jacob Zuma, has revealed deep divisions within the party.

Mr Mbeki is seeking a third term at the helm of the ANC...

... but the party's number two, Jacob Zuma, is favourite to win, despite allegations of corruption.

If elected, Mr Zuma will become the front-runner to take over as president in 2009, when Mr Mbeki will be obliged to step down after two terms as head of state.

But if Mr Mbeki can hold onto the party leadership, he could work to prevent Mr Zuma reaching the presidency.

The five-day conference is taking place in the country's northern town of Polokwane. It opened on Sunday.

Former President Nelson Mandela has said he is saddened by "the nature of the differences currently in the organisation".