Strong earthquake strikes in Indonesia, no tsunami threat

A 6.5-magnitude earthquake has struck off the central Indonesian island of Sulawesi, according to the US Geological Survey (USGS), while Indonesian officials said there was no tsunami threat.

The quake struck in the sea 122 kilometres southeast of the town of Modayag at a depth of 20 kilometres.

Indonesia's Meteorology, Climatology and Geophysics Agency earthquake and tsunami chief Mochammad Riyadi said that the tremor was felt in the northern part of Sulawesi island.

"There are no reports yet of damage or casualties so far, but people reported feeling the quake. We are monitoring closely," he said.

"There is no threat of a tsunami."

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