Ambassador Liu Guchang listed a series of groups that he said were active in and beyond China's northwestern Xinjiang region, among them the East Turkestan Islamic Movement.

"Judging from recent years the most real terrorist threat mainly comes from the East Turkestan terrorist forces active both within China and beyond its borders," said Liu.

"China is against terrorism in all its forms and is also against holding certain double or multiple standards when it comes to terrorism," he said.

He was speaking to journalists as the six-nation Shanghai Cooperation Organisation held exercises that started in Xinjiang on Thursday and are to continue near the Russian city of Chelyabinsk on Saturday.

The East Turkestan Islamic Movement is considered a terrorist organisation by the United Nations, as well as by the United States and other powers.

But China faces criticism that it is directing a campaign of repression against the Muslim Uighur minority in Xinjiang in the name of this counter-terrorism struggle.

Liu confirmed that President Hu Jintao will attend the Russian phase of the "Peace Mission 2007" exercises next Friday.

The exercises involve several thousand troops from the six nations of the Shanghai Cooper-ation Organisation: China, Kazakhstan, Kyrgyzstan, Russia, Tajikistan and Uzbekistan.

The organisation grew out of a regional effort to reduce military forces on member states' common borders and involves both counter-terrorism efforts and economic cooperation, described by Liu as the "two wheels" driving the organisation forward.

Chinese communist armies entered Xinjiang after the establishment of a new China in 1949, ending the short rule of the Republic of East Turkestan which was largely made up of Muslim Uighurs.