At least four people were killed and more than 48 injured when a strong 6.4 magnitude earthquake hit a rural part of China's far western Xinjiang region on Friday, Chinese officials said.

Many traditional houses in the mainly ethnic Uighur region collapsed when the shallow quake struck about 160 km (100 miles) northwest of the southern city of Hotan, according to Chinese emergency officials.

"Currently, the earthquake has resulted in four deaths, including a father and son, and more than 48 injuries," China National Emergency Broadcasting (CNEB) said on its website.

The quake was initially reported at various magnitudes up to 6.5. Several aftershocks were reported, the strongest measuring magnitude 4.8, according to the U.S. Geological Survey.

Residents of the region expressed shock at the intensity of the quake on social media, although authorities said they were optimistic the death toll would not be high.

Pictures on state television displayed minor damages. | Source: channelsnewsasia.com

"If many people are gathered in one place during an earthquake, it can lead to a serious disaster, but in this case, there were relatively few people so it isn't so serious," China Earthquake Networks Centre researcher Sun Shihong told state broadcaster China Central Television.

Pictures on social media and state television showed cracks on the walls of buildings and other minor damage. Earthquakes frequently strike China. A quake in the southwestern province of Sichuan in 2008 killed almost 70,000 people.

Xinjiang, strategically located on the borders of India, Pakistan, Afghanistan and Central Asia, is one of China's most politically sensitive regions following years of violence, blamed by the government on Islamist militants.

Exiled Uighur groups and human rights activists say the government's own repressive policies and religious and cultural restrictions have provoked unrest, an accusation the government denies.