A 5.2-magnitude earthquake that struck China's far-western region of Xinjiang on Thursday injured at least 26 people, three of them critically, state media said.

The quake occurred in an area near the ancient Silk Road city of Kashgar at a depth of nearly 35 kilometres (22 miles), the US Geological Survey said.

It toppled more than 30 housing units, a spokesman with the Jiashi County Committee of the Communist Party of China told the state-run Xinhua news agency.

The Kashgar government was not immediately available for comment when contacted by AFP.

Xinjiang is a vast region in northwest of China with a population of around 20 million, of which roughly nine million are Uighurs, a Turkic-speaking mainly Muslim ethnic minority.

Kashgar lies not far from the border with Kyrgyzstan, and boasts an old town full of houses that were built hundreds of years ago.

Authorities are in the process of destroying these houses and replacing them with buildings they say are resistant to powerful earthquakes.