A major earthquake with a magnitude of 7.0 struck off the northeast tip of Indonesia's Sulawesi island early today, geologists said, but there were no immediate reports of damage or injuries.
Indonesia's meteorology and geophysics agency issued a tsunami warning immediately after the quake struck at 1:34 am (1734 GMT Wednesday), but cancelled it about one hour later.
The epicentre of the quake was located about 320 kilometres (200 miles) north-northeast of the town of Manado, the US Geological Survey said. It struck at a depth of 33 kilometres.
The USGS initially put the magnitude at 7.5, but later revised it down to 7.0. Indonesia said the quake had measured 7.4 on the Richter scale.
Two aftershocks with magnitudes of 5.6 and 5.9 struck within an hour of the original quake, the USGS reported.
The Hawaii-based Pacific Tsunami Warning Centre sent a bulletin saying there was "no destructive widespread tsunami threat" based on available data.
The Indonesian archipelago straddles several continental plates in an area known as the Pacific Ring of Fire where seismic and volcanic activity is recorded on an almost daily basis.
Indonesia was the nation worst hit by the earthquake-triggered tsunami in December 2004 that killed more than 200,000 people in 11 countries across Asia, including over 168,000 people in Indonesia's Aceh province and Nias island.