JAKARTA, INDONESIA - AN earthquake measuring 6.1 on the Richter scale was recorded northwest of Indonesia's Sumbawa island early on Friday, but there were no immediate reports of casualties or damage, a meteorology official said.

The epicentre of the undersea quake was 90 km northwest of Sumbawa at a depth of 300 km, the Meteorology and Geophysics Agency said in an emailed alert.

'It was just a normal tectonic quake and had no tsunami potential,' said Suharjono, an official at the agency, adding that no deaths or casualties had been reported.