The groups are accused of trying to create an independent Islamic state called "East Turkestan" in the northwest Xinjiang region, which is populated by Turkic-speaking Uighur Muslims.

"East Turkestan forces inside and outside China have long plotted and executed a series of bombings, assassinations, arsons, poisoning attacks and other activities in Xinjiang and elsewhere in China," said Zhao Yongshen, an official with the Ministry of Public Security.

But Uighur and human rights activists abroad have rejected the "terrorist" tag and accuse Beijing of waging a campaign of politically motivated repression against ethnic and religious minority groups.

"China wants to have the Uighur movement silenced by any means," said Enver Can, president of a Munich-based group called the East Turkestan National Congress.

According to Beijing, the named groups carried out their attacks "to achieve their goal of undermining national unity".

China appealed to other governments to ban the groups, prohibit them from receiving support or asylum and freeze their accounts; and to prosecute and investigate the wanted individuals and hand them over to China.

But Enver Can denounced the issuing of the list and the appeal for foreign support as a "misuse" of the global war on terror.

He had seen nothing that could be connected with terrorism in his dealings with two of the four groups on the list and he doubted if the other two actually existed at all, he told BBC News Online.

The World Uighur Youth Congress and the East Turkestan Information Centre were, like his own group, simply NGOs based in Germany whose main function was to provide information, he said.

The two other groups on China's list are the Eastern Turkestan Islamic Movement (ETIM) and the Eastern Turkestan Liberation Organization (ETLO).

Chinese authorities have blamed ETIM for many of the 200 or more attacks reported in Xinjiang since 1990 and have banned the group for more than a decade.

Beijing accuses ETIM of having links to the Taleban in neighbouring Afghanistan and Osama bin Laden's al-Qaeda network, but has produced no supporting evidence.

After Chinese lobbying, the group was also banned last year by the US and the United Nations, despite criticism from diplomats who described it as defunct.