JAKARTA, Jan 22: A major 6.5-magnitude undersea earthquake rocked Indonesia's northern Sulawesi province on Sunday, the country's meteorology agency said, but there were no immediate reports of any casualties or serious damage.

The earthquake struck at 7:27 pm (1127 GMT) and was centred some 50 kilometers under the sea, 160 kilometres southeast of the North Sulawesi capital of Manado, Arif from the meteorology agency in Jakarta, said.

“So far we have had no report of casualties or serious damage,” said Bagyo, also from the meteorology agency.

He said five aftershocks followed within one hour of the initial quake.

The strongest, a 5.5-magnitude quake, struck 18 minutes after the initial shock. A second aftershock had a magnitude of 5.1 and struck 17 minutes later.

Another strong quake, of magnitude 6.1, hit the area at 1:32 am (1732 GMT), the US Geological Survey (USGS) said, but there was also no immediate reports of casualties or damage.

The latest quake, which struck 10 kilometres under the sea, hit 123 kilometers northwest of Ternate, on the Moluccas islands, according to the USGS.

After the first series of quakes, the agency said there was no risk of a tsunami after earlier warning that it was a possibility.

“After one hour we called the port authority in Manado and there was no rise in sea level. Therefore we cancel the possibility of tsunami taking place,” aid Arif. Hendarso, an officer at the National Disaster Coordination Centre, said no serious casualties and only superficial damage were reported in Manado.

“Reports we have from Manado say that only several large buildings had cracks on their walls. The reports also mention that so far, there are no serious casualties known,” Hendarso said.--AFP