Jakarta: An earthquake measuring 8.3 on the Richter scale jolted West Sumatra in Indonesia on Wednesday and a tsunami alert was issued, an official of the meteorology and geophysics agency said.

The quake struck at 7.49 p.m. local time with the epicentre 682 km southwest of Mentawai islands and at a depth of 10 km under the sea bed, the official told Xinhua.