China said yesterday that it had foiled five "terrorism groups" plotting attacks targeting the Beijing Olympics, as the government cracks down on perceived threats to the Games which open in less than a month.

In the first six months of the year, police detained 82 people in the restive far western Xinjiang region who had plotted to sabotage the Olympics, the state-run Xinhua news agency said, citing Chen Zhuangwei, police chief of regional capital Urumqi.

"Police in the regional capital also detained 66 gang members of the 'three evil forces' of terrorism, separatism and extremism, and destroyed 41 training bases of 'holy war' from January to June," Xinhua quoted Chen as saying.

The agency did not make clear whether the 66 gang members were included within the 82 detained region-wide.

The government says it has foiled a string of terrorist plots this year hatched from Xinjiang, a mainly Muslim region where Beijing accuses militant Uighurs of working with al Qaeda to bring about an independent state called East Turkestan.

Xinhua on Wednesday said that Chinese police had shot and killed five people they said were seeking "holy war" against the country's dominant Han Chinese.

In April, public security officials said authorities had foiled plots to kidnap athletes and carry out suicide attacks during August's Games. China earlier said it had foiled a plan by Uighur separatists to bring down a Beijing-bound plane.

Many Uighurs resent the migration of Han Chinese to the region and government controls on their religion and culture.

But Uighur advocacy groups deny separatists are plotting attacks in Xinjiang and accuse China of embarking on a pre-Olympic security crackdown targeting activists seeking greater freedom for the region.

"What China claims simply is not true," said Dilxat Raxit, spokesman for the exiled World Uyghur Congress. "Wanting to boycott the Games is not the same as wanting to damage them."