Beijing: China is keeping foreign travellers out of Tibet during sensitive political anniversaries.
Travel agencies contacted on Wednesday said foreign tourists would not be allowed into the Himalayan region until April 1.
It's not clear when the ban started, although some monitoring groups said it started this month.
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.
While the foreigner travel ban is an annual occurrence, the occasion of the 60th anniversary is drawing special attention from the authorities.
Amid heavy security on the ground, Tibet is almost entirely closed to foreign journalists and diplomats and information about actual conditions there is hard to obtain.
Beijing sent troops into Tibet in 1950 in what it officially terms a peaceful liberation and has ruled there with an iron fist even since.
The Dalai Lama, the highest figure in Tibetan Buddhism, fled into exile in India in 1959 after a failed uprising against Chinese rule.
With inputs from AP and Reuters