Beijing  - A video calling for attacks in China during the Olympics games was placed in the internet Saturday by a purported Uighur separatist group.

In the three-minute-long video, a shrouded person claiming to be a commander of the Turkestan Islamic Party also claimed that the group was behind a series of explosions in China in the past months.

The video made reference with pictures seemingly taken off the Chinese internet of the July 21 attacks on buses in China's southern Yunnan province and a May 5 attack in Shanghai.

Experts however questioned the authenticity of the video, US authority on the Uighur people, Dru Gladney, told Deutsche Presse- Agency dpa.

Exile Uighur groups have so far not called for any disturbances during the Olympic Games.

International security experts have linked the Turkestan Islamic Party with the East Turkestan Independence Movement (ETIM), both of which are considered terrorist groups by China and the United States.

Gladney however pointed out that the ETIM has not been in operation for years. The movement, should it still exist, he said, did not have many adherents to begin with, adding that the China generally uses the name ETIM as label for all Uighur independence groups.

Chinese security authorities have not made any connection between the Olympics and the previous attacks mentioned in the video, but they assume that Uighur groups would attempt attacks during the games.

Xinjiang province in north-western China is along with Tibet a source of political tension in China. The territory's Turkic Muslim Uighurs have complained of repression by Chinese authorities. After the founding of the People's Republic of China in 1949, the former East Turkestan was annexed as an autonomous region - in a similar manner to Tibet.

Exile Uighurs call for the reestablishment of a former East Turkestani republic. (dpa)