At least 67 people were killed and 731 injured when two earthquakes struck a remote and mountainous area of southwest China on Friday, toppling houses and sending panicked crowds onto the streets.

Residents described how people ran out of buildings screaming as the two shallow quakes hit on the border of Yunnan and Guizhou provinces an hour apart around the middle of the day. They were followed by a string of aftershocks.

Authorities were sending thousands of tents, quilts and coats, and Premier Wen Jiabao was also heading to the area, the state Xinhua news agency said, confirming the death and injured toll, which rose steadily throughout the day.

The US Geological Survey said the first quake struck at 11.20 am (0320 GMT) at a depth of around 10 kilometres (six miles), with the second quake around an hour later, putting the magnitude of both at 5.6.

The earthquakes cut off electricity and triggered landslides, blocking roads, which was complicating the rescue mission, Xinhua said.

Li Fuchun, the head Luozehe township, identified as the epicentre, told Xinhua: “Roads are blocked and rescuers have to climb mountains to reach hard-hit villagers.”

Peng Zhuwen, a worker at a zinc mine in Luozehe, added: “It is scary. My brother was killed by falling rocks. The aftershocks have struck again and again. We are so scared.”