Even as Jiang Yu, the Foreign Ministry spokesperson, declined to react to reports that the travel agents have been asked not to make bookings for visiting Tibet, officials said the curbs were due to heavy wintry weather.

Asked during the media briefing here today about reports quoting travel agents in this regard, Jiang said the question should be directed to local authorities.

Confirming the curbs, Zhang Qingli, the Communist Party of China (CPC) chief for the Tibet, said at the parliament session here that the "temporary measures" on restricting foreign tourists to the region were mainly due to the current cold winter weather, limited accommodation capacity and safety concerns.

"The plateau region is still in deep freeze in March and lots of religious activities will be held. Local authorities do not hope there is something wrong with foreign tourists," Zhang who is attending the ongoing session of the National People’s Congress (NPC) was quoted as saying by the Xinhua news agency today.

Travel to Tibet is already restricted and foreign media has to take obtain special permission to visit the region.

Zhang defended the curbs on foreigners, saying many people are visiting Tibet to attend a grand ceremony being organised to  commemorate the 60th anniversary of the "liberation" of Tibet by the Chinese Army.

As a result there is great pressure to the limited number of hotels in the region, Zhang said.

Ahead of the March 14 anniversary of the 2008 riots in which 18 people were killed and 400 wounded, Chinese officials have stepped up attack against the Tibetan leader Dalai Lama.

Dalai Lama is a "wolf in monk's robes", Zhang said, as he yesterday accused the 76-year-old exiled Buddhist leader of seeking separation of Tibet from China.

Underplaying the importance of the 1989 Nobel laureate, former Tibet Governor Qiangba Puncog told the media in Beijing that when Dalai Lama dies, it will trigger small shock waves in Tibet but won't result in serious instability.

The exiled spiritual leader still has religious clout but no political influence in China, he added.

China has accused the followers of Dalai Lama for instigating the the 2008 violence, a charge the exiled leader has denied.