London - Britain's Princes William and Harry will take part in a gruelling off-road motorcycle rally in South Africa later this month, Clarence House in London said Wednesday.

The two brothers, aged 26 and 24, were "looking forward to the motorcycle ride," with the proceeds from the Enduro Africa 08 event going to charity.

Money raised from the adventure will be divided equally between Sentebale, a charity established by Harry to help disadvantaged children, UNICEF and the Nelson Mandela Children's Fund.

The princes, both accomplished riders and motorbike owners, will be among around 80 people riding across the tough terrain.

The royal brothers will join groups of eight to 10 riders travelling together during the day with all 80 volunteers camping together at night.

A spokesman for Global Enduro, an adventure company which runs the Enduro Africa event, said since both princes were in the army, they would "have the grit to get through because it's not easy."

"There are no road signs and it's not like riding anywhere in the UK so they will need a guide. They will go through game reserves, tribal areas and wild areas," he said. (dpa)