Shanghai - Icelandic pop singer Bjork backed independence for Tibet during her concert on Sunday in Shanghai, eyewitnesses said on Monday.
She shouted 'Tibet, Tibet!' followed by 'Raise your flag!' towards the end of her final song, 'Declare independence.'
Her protest apparently went unnoticed by the majority of an estimated 3,000 people at the Shanghai International Gymnastics Centre.
But it is likely to anger China's communist government, which has previously expelled foreigners for making public protests in favour of Tibetan independence.
The words 'Raise your flag' are part of the standard lyrics of the song.
A representative of the Chinese concert organizer, Shanghai-based Emma Entertainment, said by telephone that she had been backstage and was unaware of Bjork shouting 'Tibet, Tibet!' The company declined further comment on the incident.
At a similar concert in Tokyo last week, Bjork dedicated her performance of 'Declare independence' to supporting Kosovo's declaration of independence.
That statement led organizers of a Serbian music festival planned for July to drop her from the lineup, citing security fears.
Her Shanghai protest came as several Tibetan independence groups are running high-profile campaigns to promote their cause ahead of the Olympic Games in Beijing in August.
Most Tibetans support calls by the exiled Dalai Lama, Tibetan Buddhism's highest leader, for greater autonomy for Tibet within China, although many still favour independence.
The Dalai Lama fled to India in 1959 after an abortive uprising against the occupation of Tibet by Chinese troops since 1951. He remains as popular as ever among ordinary Tibetans.