A 7.8-magnitude earthquake struck off Sumatra island in western Indonesia Wednesday, local officials said, triggering a tsunami warning.

A 7.8-magnitude earthquake struck off Sumatra island in western Indonesia Wednesday, local officials said, triggering a tsunami warning.

The quake struck at a depth of 10 kilometers (six miles), triggering a tsunami alert for parts of Sumatra, including West Sumatra, North Sumatra and Aceh, the local BMKG quake monitoring agency said.