Rebellion fears: China ban on foreigners in Tibet until April 1

China is barring foreign travellers from Tibet over a period of several weeks that includes a pair of sensitive political anniversaries questioning the legitimacy of Beijing's rule over the Himalayan region.

Travel agencies contacted Wednesday said foreign tourists would not be allowed back into Tibet until April 1. It's not clear when the ban started, although some monitoring groups said it began this month.

The ban was confirmed by the online customer service portal of the Tibet Youth International Travel Service, as well as staff at the Tibet Vista and Go to Tibet travel agencies. Both are based in the southwestern city of Chengdu — the main jumping-off point for visits to Tibet. Staff members declined to give their names or offer details. March 10 is the 60th anniversary of an abortive 1959 uprising against Chinese rule in Tibet, while anti-government riots occurred March 14, 2008, in the regional capital Lhasa.

Although the foreigner travel ban is an annual occurrence, the occasion of the 60th anniversary is drawing added attention.

Amid heavy security on the ground, Tibet is almost entirely closed to foreign journalists and diplomats and information about actual conditions there is difficult to obtain.

The 1959 uprising resulted in the flight of Tibet's traditional Buddhist leader, the Dalai Lama, into exile in India and the beginning of increasingly harsh Chinese rule over the region.

Nearly five decades later, anger exploded in a series of protests in an around Lhasa that culminated in attacks on Chinese individuals and businesses in which the government says rioters killed 18 people. An unknown number of Tibetans were killed by security forces in the aftermath.