A massive earthquake struck off the coast of the Indonesian island of Sumatra on Wednesday, triggering a tsunami watch for the Indian Ocean.

The magnitude 8.6 quake struck about 500 kilometers from Indonesia’s Aceh province, the U.S. Geological Survey said. It took place at a depth of 33 kilometers.

The Pacific Tsunami Warning Center initially issued a tsunami watch for the entire Indian Ocean, but the watch has been cancelled.

Banda Aceh was devastated by a tsunami resulting from an earthquake in December 2004.

[Updated at 9:04 a.m. ET] The Pacific Tsunami Warning Center has cancelled its tsunami watch in the Indian Ocean.

“Sea level readings now indicate that the threat had diminished or is over for most areas,” the center said.