China and Tajikistan have officially opened their shared border at a pass high in the Pamir Mountains.
By Monica Whitlock
BBC Central Asia correspondent
State officials from Xinjiang province in western China and the Prime Minister of Tajikistan, Aqil Aqilov, cut a red ribbon at the mountain village of Kulma, sending a fleet of ceremonial trucks across to the Chinese side.
The border was sealed tightly for almost a century during the Soviet time but now trade is growing and China is fast becoming an economic power in Central Asia.
The opening brings real possibilities to a remote and undeveloped region.
The Kulma Pass must be one of the highest trading routes on earth. Set among the towering peaks of the Pamir, the border is over 4,000 metres high.
Traders expect a flood of Chinese imports to cross the mountains from Xinjiang.
The bazaars of Tajikistan are already full of Chinese wares like clothes, shoes and household goods.
Up to now they have been trucked mainly through neighbouring Kyrgyzstan.
Opening the road through Kulma means a shorter route and cheaper prices and a possibility of trading onwards to other parts of Central Asia, where Chinese products are now bought as standard.
In the longer term, the Tajiks hope to import the machinery and technology they badly need to modernise their country.
It is also a chance for the Tajiks to reach the Karakorum highway that winds down to Pakistan and the ports of South Asia.