Jakarta, Indonesia (CNN) -- A massive earthquake struck off the coast of the Indonesian island of Sumatra on Wednesday afternoon, triggering a tsunami alert for the Indian Ocean.
The quake struck about 434 kilometers (270 miles) southwest of Banda Aceh, the capital of Indonesia's Aceh province, and had a magnitude of 8.6, the U.S. Geological Survey said. It took place at a depth of 23 kilometers (14 miles).
A second quake, magnitude 8.2, occurred off the west coast of Sumatra about two hours later, the USGS said.
