The magnitude-6.1 quake struck on Tuesday afternoon at a depth of just 10 kilometres (6 miles) and was centred 55 kilometres (34 miles) west of the town of Bireun on the western tip of Sumatra island, the U.S. Geological Survey said.

Twelve people were killed and 70 others were injured by a landslide or collapsing buildings in Bener Meriah, said Sutopo Purwo Nugroho of the National Disaster Mitigation Agency. He added Wednesday that the number of houses and buildings damaged in the district is still being counted.

In neighbouring Central Aceh district, 10 people died, 140 were injured and about 1,500 houses and buildings were damaged, Nugroho said. The quake also triggered landslides and caused hundreds of people to be evacuated to 10 temporary shelters.

At least 25 of the injured in Bener Meriah were admitted to hospital in intensive care, deputy district chief Rusli M. Saleh said.

“We are now concentrating on searching for people who may be trapped under the rubble,” Saleh said. More than 100 houses and buildings were damaged in the district, he said.

“I see many houses were damaged and their roofs fell onto some people,” said Bensu Elianita, a 22-year-old resident of Bukit Sama village in Central Aceh district. “Many people were injured, but it is difficult to evacuate them due to traffic jams.”

She said people in the village ran out of their homes in panic and screamed for help. At least two houses were totally flattened, she said, and the power failed in the village.

The quake also caused concern among officials attending a meeting of the Asia Pacific Economic Cooperation forum in Medan, the capital of neighbouring North Sumatra province. They were escorted from the second-floor meeting room by security officers.

Indonesia is prone to seismic upheaval due to its location on the Pacific Ring of Fire, an arc of volcanoes and fault lines encircling the Pacific Ocean.

In 2004, a magnitude-9.1 earthquake off Aceh triggered a tsunami that killed 230,000 people in 14 countries.