Police descended on a group of foreign pro-Tibet activists and some disgruntled business owners from Hong Kong on Thursday, taking both groups away minutes after they displayed protest signs in central Beijing.
The abrupt end of the separate protests underscores China's determination to prevent any disruption during the Olympics.
The government has said it would allow protests in three areas during the games, but no application to hold a demonstration has been accepted. One of the Hong Kong protesters on Thursday, Wang Pei, told The Associated Press his group also tried to submit an application.
Earlier, police seized four activists protesting Chinese rule in Tibet as they unfurled a Tibetan flag and shouted ``Free Tibet'' south of the National Stadium, the New York-based Students for a Free Tibet said.
The group put the number of police at 50. A spokeswoman for the Beijing Public Security Bureau declined comment, and the whereabouts of the activists was not known.
Two Associated Press photographers were roughed up by plainclothes security officers, forced into cars and taken to a nearby building where they were questioned before being released. Memory cards from their cameras were confiscated.
Information for this report was provided by AP.