Bjork has a track record of courting controversy and surprising her fans

The cry followed a powerful performance of her song Declare Independence.

Talk of Tibetan independence is considered taboo in China, which has ruled the territory since 1951.

Although some at the concert appear not to have heard Bjork's protest on Sunday, there was an uneasy response from other fans.

Shocked fans

After the concert, held at the Shanghai International Gymnastics Centre, some negative reactions were posted on Chinese websites.

Wow, the nerve! Where did she get the courage to do this? Weirdo! Comment on Chinese website

"I like Bjork", said one, "it's OK for her to have a different point of view, but for her to do this is disrespectful to fans here - very selfish of her".

Another fan said Bjork had "behaved like an angry young person, acting in an underhand manner, not like Brad Pitt and Richard Gere, who are better known Free Tibet supporters".

According to one audience member, there was no booing after the outburst, but people left the concert venue hurriedly.

Human rights activists and many politicians abroad have criticised Chinese policy in Tibet. Many Tibetans feel loyal to the exiled spiritual leader, the Dalai Lama, whom China considers a separatist threat.

The song Declare Independence has previously been used by Bjork to highlight other struggles for self-rule.

She dedicated a performance of it in Japan last month to Kosovo. She has also used the song to campaign for Greenland and the Faroe Islands - territories controlled by Denmark.

Bjork performed in two Tibetan Freedom Concerts in the United States in the 1990s.

Her behaviour at the Shanghai concert has not been reported in the state-controlled Chinese media.