Euphoric Chinese crowds chanting “Go Olympics, Go Beijing” cheered the Olympic flame through the capital on Wednesday at the end of its troubled global relay. A handful of foreign protesters took their chance to grab the spotlight before attention shifts on to the sporting contests. Police rushed to detain two Britons and two Americans who unfurled “Free Tibet” banners from poles near the main “Bird's Nest” stadium, and stopped other public protests during the day. The mood in Beijing, though, was one of mounting excitement, with most of the 10,500 athletes from 205 countries now in town. In Tiananmen Square, Beijing's symbolic heart best-known abroad for the crushing of 1989 protests, one of China's most famous sportsmen, 7ft 6in basketball player Yao Ming, said he was overwhelmed as he held the flame above a sea of beaming faces. “After lighting it, my mind went blank, and then I just wanted to hurry up running ahead,” said Yao, according to official news agency Xinhua. Children wore “I Love China” T-shirts and workers waved flags and pom-poms, while drums and cymbals resounded around Tiananmen under a portrait of late revolutionary leader Mao Zedong. The Games have given China an unprecedented chance to showcase its modern face and economic progress but have also galvanized critics of its human rights record. As organizers made final preparations for Friday's opening ceremony at the futuristic “Bird's Nest” Olympic stadium, disputes over an array of issues persisted. Four activists from Students for a Free Tibet staged a dare-devil protest near the Olympic stadium by climbing up an electricity pole and unfurling two giant banners. The banners, which read “One World, One Dream: Free Tibet” and “Tibet Will Be Free”, were up for an hour before police ripped them down and detained the protesters, two Americans and two Britons, the group said. Pollution remains another headache for the organizers. But even though a blanket of smog hung over the city on Wednesday, the authorities insisted they had no plans to invoke extra emergency measures to improve air quality.