A Tibetan rights group says Chinese police have detained six protesters who unfurled a banner on the Great Wall calling for a free Tibet.
The Free Tibet Campaign said the banner read "One World, One Dream, Free Tibet 2008." "One World, One Dream" is the motto for the 2008 Beijing Olympics.
The group says the protesters were on the wall for about two hours before being detained. Further details were not immediately available.
On Monday, an international media rights group held a rare protest in Beijing against China's continued harassment of journalists one year before it hosts the Olympics.
Several members of Reporters Without Borders demonstrated outside the headquarters of the Games' organizers.
Shortly afterward, about 20 Chinese policemen scuffled with the activists and other foreign journalists covering the protest. Police detained the journalists in a parking lot and released them about an hour later, without explanation.
A member of the media rights group Robert Menard says China has not fulfilled promises it made to improve media freedoms ahead of the Games.
The games' organizing committee said Monday it welcomes constructive criticism from foreign journalists. But, it also rejected any attempts by foreign groups to politicize the Olympics.