BEIJING, Nov 30 (Reuters) - China called on Wednesday on Taiwan to stay out Hong Kong's affairs, saying self-ruled Taiwan was "talking nonsense" about the former British colony and warning it not to damage Hong Kong's stability.

Chinese leaders are concerned about a fledgling independence movement in Hong Kong, which returned to mainland rule in 1997 with a promise of autonomy, and recent protests in the city.

Beijing staged a rare interpretation of Hong Kong's mini-constitution, the Basic Law, in early November to effectively bar pro-independence city lawmakers, Baggio Leung and Yau Wai-ching, from taking office there.

The pair lost an appeal on Wednesday into an earlier Hong Kong court ruling that disqualified them after they insulted China while taking their oaths last month.

Three Court of Appeal judges ruled that Yau, 25, and Leung, 30, had no grounds to re-take their oath as a matter of law.

Yau and Leung, elected in September polls, have yet to confirm earlier plans to take their case to Hong Kong's highest court, the Court of Final Appeal.

Asked about comments from legislators from Taiwan's ruling Democratic Progressive Party (DPP), which favours the island's formal independence, offering support for Leung and Yau, China's Taiwan Affairs Office said independence activists from both sides were trying to link up and sow chaos in Hong Kong.

"Compatriots on both sides of the Taiwan Strait, especially those in Hong Kong, should be on high alert for this," spokesman Ma Xiaoguang told reporters in Beijing.

"The words and deeds of Baggio Leung and Yau Wai-ching run contrary to mainstream public opinion in Hong Kong and Hong Kong resident's basic interests, but relevant parties in Taiwan are helping them, to what intent?" Ma asked.

"We advise the Taiwan side not to talk nonsense about the Hong Kong issue, interfere in Hong Kong's enforcement of 'one country, two systems', or damage Hong Kong's prosperity and stability," he said.

Hong Kong returned to China under a "one country, two systems" agreement that ensured its freedoms and wide-ranging autonomy, including a separate legal system.

But Communist Party rulers in Beijing have ultimate control, and some Hong Kong people are concerned they are increasingly interfering to head off dissent.

China considers self-ruled Taiwan a wayward province and has never renounced the use of force to bring it under its control. Defeated Nationalist forces fled there at the end of a civil war with the Communists in 1949.

Relations between China and Taiwan have worsened since the election of the DPP's Tsai as Taiwan president in January. (Reporting by Ben Blanchard in Beijing and Pak Yiu in Hong Kong; Editing by Robert Birsel)

Our Standards: The Thomson Reuters Trust Principles.