A magnitude 7.0 earthquake has hit south-western China, killing at least 56 people and injuring more than 600.

The Chinese seismological bureau initially measured the quake at magnitude 7. Strong jolts toppled buildings at 8am local time, sending people into the streets in their underwear and wrapped in blankets.

2,000 troops have been dispatched to assist in clearing the area and helping rescue efforts.

Lushan, where the quake struck, is home to 1.5 million people. Known for its mountains, the area is near a well-known preserve for pandas.

The quake struck near the area where another devastating earthquake left 90,000 dead or missing and presumed dead in 2008.