TAIPEI, Taiwan — The 100-strong Chinese delegation boycotted the opening ceremony of the World Games in Taiwan on Thursday, underscoring the limits of the historic breakthrough in relations between Taipei and Beijing.

The Chinese gesture is likely to ruffle feathers on this democratic island of 23 million people, which under President Ma Ying-jeou has moved aggressively to improve ties with the mainland, its once-bitter enemy.

While the Chinese delegation did not say immediately why it boycotted the ceremony — a comment on state-run China News Service acknowledged the presence of Chinese athletes in Taiwan, without mentioning the opening ceremony — the act is almost certainly related to Ma's role in declaring the games open.

In his opening remarks, Ma simply declared the games to have begun, without mentioning the boycott.

Taiwan and China split amid civil war in 1949 and the communist mainland still views the island as part of its territory. Because of this claim Chinese attendance at the ceremony could have been seen as lending legitimacy to Ma's presidential role. That would contradict Beijing's long-standing position that Taiwan lacks state sovereignty.

Under a hazy summer sky in the southern city of Kaohsiung, more than 3,000 athletes and staff from 105 countries and territories marched into the World Games Stadium, a new, eye-catching structure designed by renowned Japanese architect Toyo Ito.

But under the gaze of the capacity crowd of 40,000, the Chinese team was absent from the ceremony, with a single Taiwanese staff member carrying a sign marked "China," and another carrying a Chinese flag.

Some in the crowd applauded this representation of the communist colossus to the west, but many booed, in a clear sign of displeasure with the Chinese action.

The mainland's boycott stands in contradiction to the rapidly improving relations between the sides.

Since taking power 14 months ago, Ma has jettisoned his predecessor's pro-independence policies, tightening economic links with the mainland, and lowering tensions across the 100-mile- (160-kilometer-) wide Taiwan Strait to their lowest level in 60 years.

Ma believes that the two sides can nurture their friendship while putting political questions on the back burner, and has expressed consistent support for a formal peace treaty with Beijing.

Most Taiwanese support his policies, though events like the World Games boycott do not help the mainland's image on the island, which is already undermined by perceptions that it is austere and overbearing.

Taiwan invested about $220 million in the World Games, a quadrennial event featuring 21 non-Olympic sports, like sumo and rugby.

Many Taiwanese see it as a golden opportunity to stretch the limits of the island's international isolation — it is absent from bodies like the United Nations, and is recognized by only 23 countries — and do not appreciate moves to restrict its space.

In a contrary display, they broadly welcomed Beijing's acquiescence in permitting Taiwan to attend the May meeting of a U.N. health body as an observer.

Political scientist Lo Chih-cheng of Soochow University said that after the Chinese delegation's snub many Taiwanese will raise tough questions about Ma's cross-strait policy.

"Ma has been telling Taiwanese that Beijing accepts his claim that Taiwan and China can agree to differ on whether the two sides belong to the same country, but the Chinese delegation's no-show has contradicted that," said Lo, who generally supports the pro-independence opposition. "This will lead people to question the legitimacy of Ma's statements."

But fellow political scientist George Tsai of Taipei's Chinese Culture University — usually a supporter of the government — said that China had shown goodwill by allowing Ma to preside over the opening ceremony.

"Beijing could demand the World Games follow Olympic rules and forbid Ma to attend, but it didn't," Tsai said. "This shows Beijing has made concessions."