At least 47 people were killed after a powerful magnitude 7.7 earthquake struck off Indonesia’s Flores Island early Saturday, triggering landslides, damaging buildings and briefly prompting a tsunami warning.

The earthquake struck off the coast of East Nusa Tenggara province at a depth of about 10 kilometers, according to seismic authorities. The shallow quake caused heavy shaking across the region and was followed by numerous aftershocks.

Officials said more than 150 homes collapsed, while nearly 200 others were damaged. Schools, churches and other public facilities were also affected. About 2,000 residents were evacuated as authorities assessed the destruction.

Rescue efforts were complicated by landslides that blocked roads and by power and communications outages. Authorities initially issued a tsunami warning for parts of the region, but later lifted it after monitoring showed the threat had diminished. Waves of up to about 1.6 meters were recorded in one coastal area.

A separate magnitude 6.9 earthquake later struck North Sumatra, although there were no immediate reports of major casualties or damage from that tremor.