The flame for the Aug. 8-24 Beijing Olympics has been lit using the sun's rays at a ceremony in Ancient Olympia. IOC President Jacques Rogge attended the ceremony at the site in southern Greece where the ancient Olympics were born. An actress dressed as a high priestess lit the flame using the sun's rays harnessed a convex mirror. Earlier, two pro-Tibet demonstrators ran onto the field at Ancient Olympia while Lieu Qi, president of organizing committee of Beijing 2008 Olympic Games, was giving a speech. Police detained the two men. Lhadon Tethong, director of Students for a Free Tibet, said both men were taken to the local police station. "One of our colleagues saw them being dragged by about 20 police through town," Tethong told The Associated Press. The ceremony was held an hour early - starting at 0900GMT - to avoid rain forecast for later Monday. The ancient site was damaged by wildfires last year, prompting a massive replanting effort. At Sunday's final rehearsal, clouds over the ancient games' ruined birthplace prevented organizers from kindling the torch for the 2008 Olympics in the traditional way - using the mirror. Instead, a Greek actress in the white gown and sandals of a pagan high priestess used a backup flame lit at a rehearsal on Saturday. That flame would have been sent to China if storms forecast for Monday had scuttled the official lighting ceremony beside the 2,600-year-old Temple of Hera in ancient Olympia. Clouds spoiled the ceremony for the 2000 Sydney Olympics and the last three Winter Olympics. Regarding Tibetan protesters, a Greek government official said politics had no place at the ancient site. "We are determined to safeguard the flame ceremony," he said, on condition of anonymity because he was not authorized to comment on the event. "This has nothing to do with political disputes." Tibetans and their supporters have protested in cities around the world against China. Some fear the arrival of the Olympic torch - scheduled to travel through 20 countries before the Beijing Olympics open on Aug. 8 - could spark violent protests against China.