A powerful earthquake struck the southern Philippines on Thursday, crushing a man under falling debris and sparking searches of seriously damaged buildings that had already been rattled by two previous deadly tremors.

The 6.5 magnitude quake hit the island of Mindanao, the US Geological Survey said, causing locals to run to safety in the same area where a strong tremor killed eight people on Tuesday.

The powerful shaking caused serious damage to a condominium building in the major southern city of Davao, which was about 45 kilometres from the epicentre.

A collapsed structure in another town crushed and killed a local official who was inside to help with an improvised medical treatment centre set up after the previous quakes.Locals have been left terrified by a string of powerful quakes, and hundreds of aftershocks since the first powerful tremor struck on October 16.

“Everyone rushed outside,” said Reuel Limbungan, mayor of the Tulunan town, which was once again near the epicentre. “It was as strong as the previous one.” Hundreds of families on Mindanao island, which makes up the southern third of the Philippines, have been living in shelters because they are afraid to go home.USGS initially said the quake had a magnitude of 6.8, and added there was no threat of a tsunami.