A 6.8-magnitude earthquake struck northern Sumatra in Indonesia on Saturday, hours after at least 38 people were killed when a 7.7-magnitude earthquake struck off eastern Indonesia, according to the German Research Centre for Geosciences (GFZ).

The latest quake struck at a depth of 158 km (98 miles), GFZ said.

Earlier on Saturday, the 7.7-magnitude earthquake struck off the coast of Indonesia’s Flores region, prompting a tsunami warning for parts of East Nusa Tenggara. The quake occurred at around 3.28am IST, with the epicentre located at 8.557°S latitude and 121.181°E longitude.

The earthquake triggered landslides and power outages, while communications were disrupted in parts of the affected region. Rescue teams were yet to reach Nagekeo, the area closest to the epicentre, as landslides blocked road access.

Videos and images circulating on social media showed buildings reduced to rubble, thick clouds of dust rising from collapsed structures and people running into the streets as powerful shaking swept across the region. Rescue and relief operations were under way across the country.

“The quake was massive, the shock was so strong, we were resting at home with family,” said Nona, a 51-year-old resident of Talibura, as quoted by Reuters.

“There were 13 of us inside the house and we all ran to save ourselves,” she recounted.

At least 13 people were injured, including two seriously, while about 2,000 residents fled their homes for temporary shelters, according to Indonesia's National Disaster Management Agency.

The head of the Maumere Search and Rescue Agency, Fathur Rahman, said rescuers continued searching for two villagers believed to be buried under mud following a landslide triggered by the earthquake.