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 on 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.