A pro-Tibetan protester was jostled by pro-China demonstrators who tried to snatch her Tibetan flag Monday during Chinese President Hu Jintao's visit to Austria, witnesses said.

Two policemen came to the aid of the woman from the "SOS Tibet" group as President Hu emerged from his hotel to go to the Imperial Palace to meet Austrian President Heinz Fischer.

"All that because he (Hu Jintao) does not want to see our flag," said the woman, a lone pro-Tibetan protester among the group of around 40 Chinese waving the Chinese and Austrian flags.

Austrian authorities banned pro-Tibetan protests near Hu's hotel and most anti-Beijing demonstrators gathered instead outside the Burgtheater, Vienna's biggest theatre.

Hu is on a two-day visit to Austria prior to attending the G20 summit of the world's top economic powers in Cannes, France, on Thursday and Friday.

Several demonstrations are planned during Hu's visit, with pro-Tibetans denouncing a Chinese crackdown in the territory.

Tight security was in place and parts of the city centre were also to be shut down.

China has ruled Tibet since 1951, a year after sending in troops to "liberate" the region.