A 6.2-magnitude earthquake struck off the central Indonesian island of Sulawesi on Wednesday, according to the US Geological Survey (USGS), sending panicked residents running from their homes.

The USGS initially reported the quake's magnitude at 6.5 but later revised it down.

The quake struck in the Molucca Sea between Sulawesi and the Maluku chain of islands, but Indonesian officials said there was no threat of a tsunami.

The tremor was felt in the major cities of Manado and Gorontalo in northern Sulawesi.

"People in Manado felt the quake and ran from their homes," national disaster agency spokesman Sutopo Purwo Nugroho said.

A hotel receptionist in Gorontalo said he felt a light tremor for around five seconds.

"Our guests didn't panic but they stayed where they were until the shaking stopped," he told AFP.

The quake struck around 130 kilometres (80 miles) southeast of the town of Modayag at 0246 GMT, at a depth of 30 kilometres, according to the USGS revision.

Indonesia's Meteorology, Climatology and Geophysics Agency said that there were no immediate reports of damage or casualties.

Indonesia sits on the Pacific "Ring of Fire" where continental plates collide, causing frequent seismic and volcanic activity.