A strong undersea earthquake struck off the coast of Indonesia?s Sulawesi island yesterday, prompting local authorities to warn of the possibility of a tsunami, a meteorology and geophysics official said.

Local officials said there were no immediate reports of any deaths or damage after the quake which they put at 6.6 magnitude, but the authoritative US Geological Survey said the earthquake?s magnitude was 6.1.

The quake comes less than a week after a powerful undersea earthquake triggered a tsunami on the south coast of Java island, killing nearly 700 people.

Fauzi, the head of the local meteorological agency?s earthquake centre, said yesterday?s quake was at a depth of 62 km under the sea and the epicentre was 90 km southeast of the city of Gorontalo. ?A tsunami hasn?t taken place but people have been evacuated to higher ground,?said Fauzi.

However, Stuart Weinstein of the Pacific Tsunami Warning Center in Honolulu, Hawaii, said no bulletin had been issued and the magnitude of the earthquake was around 6.1, under the threshold for a specific tsunami warning.

?The Pacific Tsunami Warning Center did not issue a specific warning for this event. The earthquake was 6.0, 6.1 in that range and our threshhold is 6.5.? Indonesia?s 17,000 islands sprawl along a belt of intense volcanic and seismic activity, part of what is called the ?Pacific Ring of Fire?.