Jakarta - The powerful undersea earthquake that struck Indonesia's North Sulawesi province and nearby regions early Monday killed at least one person and collapsed at least 100 buildings, officials said.

The quake at 01:02 am (1702 GMT Sunday) measured 7.7 on the Richter scale. Its epicentre was located about 138 kilometres north- west of Gorontalo on North Sulwesi and it occurred about 10 kilometres beneath the seabed.

A series of aftershocks followed the powerful quake, with the highest measuring 6.0 on the Richter scale, sparking a further panic among residents and preventing them from returning to their homes.

Thousands of residents in Gorontalo, Palu and other regions remained outdoors six hours after the quake. They were staying in the hills for fear of tidal waves despite the lifting of the official tsunami warning.

In the district of Buol Toli-toli in central Sulwesi province at least 100 homes collapsed. More than 20,000 residents fled their homes, the state-run Antara news agency and Elshinta private radio reported.

At least one person was killed in the quake and a number of school buildings collapsed in northern Gorontalo, Rustam Pakaya of the crisis centre at the Health Ministry said. dpa