A powerful magnitude 7.7 earthquake struck off the coast of Indonesia on Saturday, damaging buildings and homes, killing at least 20 people and causing panic in a region prone to deadly quakes. Witnesses reported collapsed buildings, including structures at a port terminal in Maumere. The partial collapse of the structures was caught on camera, with the footage also showing locals running away in fear, and others seeking shelter out in the open. Authorities said six people were injured and at least two remained missing after a landslide triggered by the quake, which hit the Flores region with a depth of 10 kilometers at 0558 local time (2158GMT Friday). The U.S. Geological Survey said the epicenter was 68 kilometres (42 miles) north-northwest of the city of Ende in East Nusa Tenggara province. The initial quake was followed by several aftershocks. Authorities earlier issued a tsunami warning for parts of eastern Indonesia, prompting residents to flee coastal areas, but the alert was lifted after no significant sea-level changes were detected. Indonesia is highly prone to earthquakes and volcanic activity.