The locals call Tajikistan's Badakhshan region the roof of the world. BBC Persian TV's Sohrab Zia visited the region, high in the Pamir mountains on the border with China and Afghanistan.

For six months of the year, Badakhshan is cut off from the rest of the country as winter snows and spring mudslides close the road to the regional capital, Khorog.

Most Tajiks are Sunni Muslims, but the people of Badakhshan are Ismailis, a branch of Shia Islam.

Red is the colour of joy and happiness in Tajikistan. Here, local residents in Khorog are celebrating the annual 11 July holiday marking the day the present Agha Khan, Karim al-Hussayni, succeeded his grandfather to become the Imam of the Ismailis.

Munija is a 26-year-old student at Khorog university. This is her wedding day.

Like many Tajik men, Munija's new husband, Angur, spends most of the year working on a building site in Russia.

It is a happy day for Munija's extended family and the whole village has turned out to celebrate.

Murghab district is the highest and most inhospitable part of Badakhshan. Trees do not grow at this altitude and in winter the temperatures plunge to minus 50C.

The majority of the local population are nomadic ethnic Kyrgyz, who make their living breeding cattle and buffalo. Many still live in traditional felt tents called yurts. This one is 150 years old.

An old man in Murghab town bazaar, wearing a traditional Kyrgyz felt hat. It is 420km (260 miles) from here to Osh, the nearest big town in neighbouring Kyrgyzstan.

An old lady from Alichur, a tiny town in Murghab district. The official pensionable age for women in this area is 48. It is a reflection of how tough life on the land is.

Murghab sits on the main road from Tajikistan to China. It is 90km (56 miles) to the border. The crossing was opened in 2004 and is becoming an important transit route for Chinese companies targeting the Central Asian market.