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.

Gary Gibson from the Seismology Research Center in Melbourne, Australia, said the location of the second quake reduces the possibility of a tsunami.

There were no immediate reports of destruction or deaths Wednesday.

Indonesian President Susilo Bambang Yudhoyono said on local television that there were no reports of casualties or damage in Aceh.

The Pacific Tsunami Warning Center issued a tsunami watch for the entire Indian…