Rocks and boulders tumbled down Mount Kilimanjaro and crashed into a group of climbers sleeping in tents Wednesday before their final ascent up Africa's highest mountain. Three tourists and an unknown number of Tanzanian guides were killed, officials said, according to AP. Five other tourists were seriously injured when the rocks crashed down from Kibo peak, Tanzania National Parks head Gerald Digurube said. They were taken to Kilimanjaro Medical Center for treatment. Several local guides were also among those killed and wounded, but it was unclear how many, said Alpine Tours owner Thomas Kimaro, who did not have any groups at the peak Wednesday but was communicating with colleagues on the mountain. About 20-30 tourists in total were involved in the accident, Kimaro said, but information on their nationalities was not immediately available. The tourists and guides _ in several climbing groups organized by various tour operators _ left Saturday for the climb. They had taken the most difficult and dangerous route to Kibo peak, Kimaro said.