Police on Friday detained five foreign tourists who were advocating a Tibet free from Chinese rule, according to state media and a group that organized the demonstration in Beijing, dpa reported.
The protest, the latest in a series by New York-based Students for a Free Tibet, happened around 5:45 am (0950 GMT) near the construction site of the new China Central Television headquarters, according to the group and the official Xinhua news agency.
Two of the pro-Tibet activists unfurled a banner which read "Free Tibet" in English and draped it over an Olympics billboard, the group said.
Police detained the protesters after about 30 minutes. The activists' whereabouts are unknown, but following previous protests, China quickly deported the demonstrators, often on the same day.
Xinhua said police ordered the five protesters to curtail their stay in China and leave the country before their originally scheduled flights.
Two activists who climbed up the billboard to unfurl the banner were Australian-Canadian and a Briton, while the three other support people were Americans, the group said.
They entered China on tourist visas, according to Xinhua.
Lhadon Tethong, the executive director of the group, said in a statement released later that the CCTV building was targetted to highlight China's practice of misrepresenting the truth about the what happens in Tibet in order to manipulate the Chinese population's views about the government's policies in the Himalayan region.
During the March and April protests in Tibet, selective images conveyed on CCTV and other state media outlets portrayed the protests as overwhelmingly violent and motivated by ethnic hatred when in fact the vast majority were peaceful and targeted at symbols of Chinese government control, the statement said.
"While the Chinese government has built a gleaming new building for its official mouthpiece and its public relations strategy has become more sophisticated, the propaganda it uses to maintain its iron-fisted control over Tibet remains the same," said Tethong.
"Tibet supporters took action at CCTV today to broadcast a message of truth about the intensifying military crackdown in Tibet and the Tibetan people's undying resolve to regain their freedom."
The group has carried out several protests in Beijing in recent days, including one near the National Stadium, or Bird's Nest, on Tiananmen Square, and outside China's Ethnic Culture Park.
The protesters were all foreign nationals, including Tibetans living overseas.