Jakarta - A powerful earthquake struck islands in the eastern Indonesian province of North Maluku Thursday, briefly triggering a tsunami warning and causing residents to flee their homes in panic, seismologists and officials said.

The tsunami alert was cancelled about 40 minutes later after no tidal waves materialized, seismologists said. There were no immediate reports of casualties or damage.

The quake struck about 7 am (0000 GMT) with was centred off Halmahera Island, about 122 kilometres north-west of Ternate, the provincial capital of North Maluku. The magnitude-7.6 tremor occurred at a depth of 10 kilometres, Indonesia's National Meteorology and Geophysics Agency said.

The US Geological Survey put the quake at a magnitude of 6.6 on the Richter scale and said it occurred at a depth of 93 kilometres.

Residents and office workers in Ternate ran out of their homes in panic, particularly after a text ran on television warning that the quake could trigger a tsunami.

Kalbi Rasyid - a local government spokesman in the West Halmahera district, the region closest to the epicentre and about 2,800 kilometres north-east of Jakarta - said there were no immediate reports of casualties or damage.

"We have deployed monitoring teams to the residential areas, in particular those on the beach area, to find out whether there are any injuries or structural damage from the quake," Rasyid said in a telephone interview.

Elshinta private radio reported that the ground shook for about 30 seconds.

On Tuesday, two people died and 60 were injured after a magnitude-5.6 earthquake struck Indonesia's South Sumatra province.

Indonesia, the world's largest archipelago nation, sits on the Pacific "Ring of Fire," an area prone to seismic upheaval because it lied on the edges of tectonic plates.

The 2004 Boxing Day tsunami was triggered by an earthquake off the north-west coast of the Indonesian island of Sumatra. It killed 230,000 people in a dozen Indian Ocean countries, 170,000 of them in Indonesia's Aceh province alone. (dpa)