A powerful earthquake rocked eastern Indonesia on Thursday, sending residents fleeing from swaying homes and hospitals, authorities and witnesses said. There were no immediate reports of damage.

The quake, which had a preliminary magnitude of 7, triggered a tsunami warning but the alert was quickly lifted after it became clear no destructive waves had been generated, the country's geophysics agency said.

world's largest archipelago, is prone to seismic upheaval due to its location on the so-called Pacific "Ring of Fire," an arc of volcanos and fault lines encircling the Pacific Basin.

In December 2004, a massive earthquake struck off Sumatra island and triggered a tsunami that killed more than 230,000 people in a dozen countries, including 160,000 people in Indonesia's westernmost province of Aceh.