Police in Kashgar, Xinjiang Uygur autonomous region, have dismantled 12 terrorist groups this year, a local official said.

All are sub-branches of transnational terrorist organizations including the "Eastern Turkistan Islamic Movement" and "Hizb-e Tahrir Organization".

Their members are generally either jobless drifters or ex-convicts, Huang Sanping, deputy Party chief of Kashgar told Hong Kong-based Takungpao newspaper.

Kashgar, in western China, borders five countries, including Tajikistan, Afghanistan and Pakistan.

"Kashgar was the site of riots in the early 1990s, but the evil forces have been steadily nipped in the bud since 2000," Huang was quoted as saying on Monday in Takungpao.

Xinjiang has been the front line of the country's battle against the terrorism owing to its geographical location. But Kashgar is not the only battleground city.

Chen Zhuangwei, head of the public security bureau in Urumqi, capital of Xinjiang, told a press conference last week that the city had already foiled five "terrorist groups" plotting attacks on the coming Beijing Olympics.

It also detained 82 people during the first six months of the year suspected of plotting to sabotage the Games.

Police also destroyed 41 Islamic militant training bases between January and June, Chen said. Senior police officers warned of "real terrorist threats to the Olympics", to begin next month.

The Ministry of Public Security said in April that it had foiled attempts by two terrorist groups in Xinjiang alleged to have been planning abductions of foreigners during the Games.