An international rights group says the legacy of the Chinese government's violent crackdown on demonstrators nearly two decades ago threatens to eclipse China's efforts to improve its image in the run up to the 2008 Olympics.

New York-based Human Rights Watch said Friday that the Chinese government has failed to account for the killings of 2,000 civilians in and around Beijing's Tiananmen Square on June 4, 1989 and in other Chinese cities.

It called on China to stop labeling the protests a "counterrevolutionary rebellion" and stop imprisoning survivors and others who have demanded state accountability.

China's hosting of the 2008 Olympic Games has become a focus of critics of the country's human rights record. But China has rejected what it says are attempts to politicize the games.

It has said that efforts to link the games to issues such as the crisis in Sudan's Darfur region will fail. But campaigners, who have dubbed the games the "Genocide Olympics," see Beijing's recent support for a United Nations mission in Darfur as an initial sign of success.

Human Rights Watch's deputy director for Asia, Sophie Richardson, says, in her words, "if the Chinese government wants to make its preferred image the reality, it is time to stop persecuting those who dare to demand justice and start prosecuting those responsible for the violence."

Five U.S. based activists were arrested on Mount Everest after unfurling banners calling for Tibetan independence and protesting China's plan to take the Olympic torch up the mountain.

The London-based rights group Amnesty International released a report in April saying that repression in China is getting worse despite Beijing's promises to improve ahead of the Olympic Games.