BANDA ACEH, Indonesia - A massive earthquake killed dozens of people and destroyed hundreds of homes in the main town on Indonesia's Nias island on Monday evening, a local government official told Metro TV.

The earthquake, centered just off the coast of Sumatra registered 8.2, according to the U.S. Geological Survey, and prompted several countries in the region to issue tsunami warnings. Residents of Banda Aceh, on Sumatra fled their homes in panic.

Like a much larger quake on Dec. 26, Monday's temblor, with a magnitude of 8.2, "has the potential to generate a widely destructive tsunami in the ocean or seas near the earthquake," the National Oceanic and Atmospheric Administration warned. It advised "immediate action" including "evacuation of coasts within a thousand kilometers (600 miles) of the epicenter and close monitoring to determine the need for evacuation further away."

Tsunami warnings were issued in Thailand, Japan and Sri Lanka.  Authorities said it could take several hours to know whether the quake had generated a devastating tsunami.

About two hours after the quake, a scientist from the Indonesia Geophysics Agency said the earthquake did not appear to have triggered a tsunami.