Beijing ? Police detained eight foreign activists and a British journalist attempting to cover their protest, as the latest in a series of demonstrations spurred jumpiness about dissent during the Olympics.

Seven of the activists were Americans; the eighth was a half-Tibetan woman with Japanese citizenship, said Lhadon Tethong, executive director of Students for a Free Tibet, the group that organized the protest.

John Ray of London-based ITV News said he was detained as he rushed to the Chinese Ethnic Culture Park, south of the main Olympic stadium, where two protesters were blocking the main entrance and unfurling a “Free Tibet” banner on a park bridge.

The demonstration was the largest in a string of brief protests in Beijing since the games began last week. Most of the demonstrations have involved fewer than five people; foreign participants have been deported.