China's first astronaut helped carry the Olympic torch through Tiananmen Square early Wednesday in front of cheering crowds, while protesters unfurled a "Free Tibet" banner near Beijing's Bird's Nest stadium.
Yang Liwei, who orbited the Earth in 2003, was one of several celebrities who held the flame. Joining him was basketball superstar Yao Ming and film director Zhang Yimou.
The torch encountered several disruptions after it first left Greece on March 24, as activists used the event to protest China's human rights record and its treatment of Tibetans. But inside China, the flame has been met by enthusiastic spectators and extremely tight security.
Despite those tightened security measures, activists managed to scale a tall lamp-posts near the Beijing National Stadium and display a banner with the slogan: "One World, One Dream, Free Tibet."
"They also unfurled a snow lion flag, the Tibetan independence flag," CTV's Steve Chao, reporting from the scene, told 麻豆影视net early Wednesday morning local time.
Sources told 麻豆影视 the activists were members of Students for a Free Tibet.
Chao said several police officers quickly amassed at the demonstration and took the protesters into custody. China claims to have 100,000 paramilitary and specially trained police working in Beijing to prevent any type of public disruption or terror threat.
Beijing Games spokesperson Sun Weide said Tuesday that China was confident about its security preparations ahead of the international event, which kicks off Friday.
"China has focused on strengthening security and protection around Olympic venues and at the Olympics Village, so Beijing is already prepared to respond to any threat," Weide was quoted as saying Tuesday.
However, on Monday, two men drove a dump truck into a group of jogging police officers in Xinjiang province -- about 5,000 kilometres north-west of Beijing -- killing 16.
Many security experts believed such an attack was a strong possibility, Chao said.
"(They predicted) it was more likely that we would see an attack in far away remote towns where there is less of a security presence," he said.
Police said the two men arrested are members of the Muslim minority Uighurs, who have waged a sporadically violent rebellion against Beijing's control of northwestern China.
"They found nine homemade bombs inside the vehicle that was used to ram into the police," said Chao.
"They also found a homemade gun as well as propaganda material... similar to the jihadist material they found during a previous raid on East Turkistan Islamic Movement groups."
Last month, a video by the Turkistan Islamic Party surfaced on the Internet. In it, the group pledged to "target the most critical points related to the Olympics."
The party is believed to be based in Pakistan, with its core members having received training from al Qaeda and the Pakistani Taliban.
Meanwhile, security in Kashgar -- where Monday's attack occurred -- has been tightened with police checkpoints on major roads.
Additionally, authorities also announced Tuesday that they've arrested 18 "foreign agitators" in the region this year.
The arrests were not all related to Monday's incident but instead linked to greater unrest in the region, said Chao.
With files from The Associated Press
