Jakarta, March 2 (RHC)-- A strong magnitude-7.9 earthquake has struck off the west coast of the Indonesian island of Sumatra, with local authorities issuing a tsunami warning.

The U.S. Geological Survey said the epicenter of Wednesday’s powerful quake was 808 kilometers southwest of Padang, but it was shallow as it struck at a depth of 10 kilometers.

According to early reports, the quake has killed some people, but it was not yet clear how many, an official of the country's search and rescue agency told Reuters. Indonesia’s National Meteorological Agency said the tsunami alert was issued for parts of Sumatra, including West Sumatra, North Sumatra and Aceh.