A 6.3-magnitude earthquake hit Indonesia's Sumatra island on Tuesday, causing panic and damage, and rocked both Malaysia and Singapore, where screaming workers rushed from trembling skyscrapers.

The quake struck underground at 10:49am (0349 GMT), the US Geological Survey said, 49km northeast of the West Sumatra capital Padang. Indonesian seismologists estimated a lower magnitude of 5.8.

The temblor was felt in cities including Bukittinggi, West Sumatra, where power cuts were reported.

Panic-stricken residents fled as houses were damaged in Solok, south of Bukittinggi, reports said. In Padang, a witness said people fled to higher ground fearing a tsunami, although the quake struck underground.

The shock was felt in Singapore, rarely hit by quakes, causing hundreds of people, some of them weeping and screaming, to evacuate high-rise offices.

There were no reports of damage or injuries in the city-state.

Singapore office worker Nicholas Wong said he felt the shaking.

"We grabbed our bags and just evacuated," he told local radio. "Everyone was panicking. One of my colleagues was crying because she had never felt such an effect before. We were all rushing out of the building."

Tremors were felt in parts of peninsular Malaysia, its meteorological department said, but there were no reports of casualties.

The west coast of peninsular Malaysia is separated from Sumatra by a narrow strait.

The Indonesian archipelago sits on the Pacific Ring of Fire where continental plates meet, causing frequent seismic and volcanic activity.