Powerful 6.7-magnitude earthquake hits Indonesia's Sumatra island, while a 6.4-magnitude quake strikes Philippines with no immediate reports on casualties in either countries.

Indonesia sits on the Pacific
Indonesia sits on the Pacific "Ring of Fire", causing it to experience frequent earthquakes. (TRTWorld)

A strong 6.7-magnitude quake has struck off the west coast of Indonesia's Sumatra island, according to the United States Geological Survey (USGS).

The quake hit at 4:06 am on Monday (2109 GMT) at a depth of 21 kilometres, with its epicentre 167 kilometres west of the coastal city of Pariaman, the USGS said.

The European Mediterranean Seismological Centre said the earthquake was of 6.8 magnitude.

"The earthquake was felt for one minute at moderate intensity as people got panic and fled their homes," said the National Disaster Mitigation Agency (BNPB) in an initial report. 

Indonesia sits on the Pacific "Ring of Fire", causing it to experience frequent earthquakes.

READ MORE: Quake strikes off Indonesia's Java island, no tsunami warning issued

Minutes earlier, a powerful earthquake struck off the Philippines' main island, jolting buildings in the capital Manila, but there were no immediate reports of damage.

The shallow 6.4-magnitude quake hit off Luzon island at 5:05 am (2105 GMT), with residents in the city woken by their buildings shaking.

Source: TRTWorld and agencies