The ban covers all flags representing countries and regions not participating in the events, they said. Demonstrations, as well as any “propaganda” appearing on banners, clothing or other accessories also will not be allowed.

Organizers said violators will be removed.

“I think most people who come to these events would hope nobody is allowed to spoil the fun and the purpose of the games,” John Breen, security coordinator for the equestrian events, told reporters in Hong Kong. The territory is hosting the equestrian competition.

China has tightened visa restrictions to keep out protesters during the Olympics, but activists could choose instead to protest in Hong Kong, which promises Western-style civil liberties denied on the mainland and grants visa-free access to citizens of many Western countries.

However, Hong Kong immigration officials turned back pro-Tibet activists who flew into the territory before its leg of the Olympic torch relay in May. Pro-democracy lawmakers also complained that police officers removed a pro-Tibet protester outnumbered by pro-China supporters during the relay.

Protests against Chinese control of Tibet marred several international legs of the torch relay.

Breen said organizers will deploy about 300 of their own security personnel at equestrian venues in addition to the 4,000 officers that police plan to mobilize.