ANCIENT OLYMPIA, Greece, Oct 18 (Reuters) - Four Tibetan activists were removed from outside the archaeological site of ancient Olympia and detained on Monday, an hour before the start of the Beijing 2022 Winter Olympics torch lighting ceremony. The activists, three women and one man, were taken to the police station in ancient Olympia, a spokesperson for the group of activists said. The spokesperson said they had neither protested nor unfurled any banners. An ancient Olympia police station official told Reuters the four had been detained, but not arrested. "We do not know yet how it will develop," the police official said. "We cannot give out any more information at this point." Two human rights activists protested in Athens on Sunday and were arrested. They had unfurled a Tibetan flag and hung a banner reading "Free Hong Kong - Revolution" from the Acropolis monument. More protests are expected on Tuesday when the flame will be handed over in Athens to Beijing Games organisers. The Chinese capital will become the first city to host both the Winter and Summer Games when it stages the Feb. 4-20 event but it faces protests and calls for boycotts over the country"s human rights record have marred the run-up. Rights groups and U.S. lawmakers have called on the International Olympic Committee (IOC) to postpone the Games and relocate the event unless China ends what the United States deems ongoing genocide against Uyghurs and other Muslim minority groups. Chinese authorities have been accused of facilitating forced labour by detaining around a million Uyghurs and other primarily Muslim minorities in camps since 2016. China denies wrongdoing, saying it has set up vocational training centres to combat extremism.