By Charles Haviland
BBC News, Everest region
Foreign climbers will now need to have a permit to get to base camp
The authorities in Nepal are closing Everest Base Camp completely to foreigners not intending to climb the world's highest peak.
They are doing this because China is worried demonstrators might disrupt their project to bring the Olympic torch up the mountain.
China is seeking to bring the torch up any day now, when weather permits.
Meanwhile, scores of Tibetan exiles have been arrested while demonstrating in the Nepalese capital Kathmandu.
Many amateur trekkers come to Nepal with Everest Base Camp as their ultimate goal.
The husbands and wives of summiteers stay in the camp before their spouses go on up.
Photographers take pictures in or near the unique encampment.
These people, if they are foreign, will now have to leave the camp until China has brought the Olympic torch to the top on the other side.
Any foreigner without a climbing permit will have to go, and on paper that includes doctors and expedition leaders too.
Nepal has imposed a communications blackout at the camp so it is impossible to know exactly who will be leaving or indeed much else that is happening.
Last week, an American with an anti-Chinese banner was sent down from the camp, and Chinese officials are concerned that Nepal should spot such people and remove them.
In another sign of Nepalese co-operation with China, police in Kathmandu arrested some 70 members of the Tibetan exile community who were trying to demonstrate in front of a Chinese embassy building.
The protests there have become an almost daily occurrence in the run-up to the Beijing Olympics.
But this time the Tibetans tried a new approach - they brought flowers which they said they wanted to give to Chinese officials, and termed them a "get well soon" bouquet for what they described as the "Chinese sickness" of human rights abuse and mediaphobia.
Nepal is unstinting in its support for its big neighbour which gives it development aid and diplomatic backing.
On Wednesday, the national sports council staged a special programme marking 100 days before the start of the Beijing games and wishing them every success.