BANDA ACEH, Indonesia — At least 18 people died and dozens were feared trapped in rubble after a strong earthquake struck off Aceh Province on Indonesia’s Sumatra island on Wednesday, officials said.

"Eighteen have died so far, based on data from the hospital. Some of the fatalities are children," said Said Mulyadi, deputy district chief of Pidie Jaya, the region hit hardest by the quake.

The shallow 6.5-magnitude quake hit just north of the small town of Reuleuet, the US Geological Survey (USGS) said. There was no tsunami alert.

The quake struck at dawn, as some in the predominantly Muslim region prepared for morning prayers, local officials said.

Mulyadi said seven children were among the dead, with a local hospital overwhelmed by the number of people arriving with injuries.

"The hospital here couldn’t take the patients, so we sent some to the neighbouring district," he said.

Mosques, homes and shops were flattened in the quake, with images from the worst-hit areas showing significant damage.

Local resident Hasbi Jaya, 37, said his family was asleep when the powerful quake struck.

"We immediately ran outside the house but it crumbled. Everything from the roof to the floor collapsed, and was destroyed," he said.

"I looked around and all my neighbours’ houses were also completely destroyed."

The local disaster management agency said rescue efforts were under way to save those trapped beneath collapsed buildings.

"Some people are still trapped inside shophouses, and we are trying to evacuate them using heavy machines and by hand," local agency head Puteh Manaf said.

Seismologists said the earthquake was felt across much of Aceh Province, which was devastated by the 2004 Indian Ocean tsunami.

At least five aftershocks followed the quake, said Eridawati, local head of the Meteorology, Climatology and Geophysics Agency.

The USGS upgraded the magnitude to 6.5 from an initial reading of 6.4 and issued a yellow alert for expected fatalities and damage.

"Some casualties and damage are possible and the impact should be relatively localised," it said.

In the coastal town of Sigli, people panicked and fled their houses to seek shelter away from the sea.

"We are now evacuating to Tijue because we are afraid of a tsunami," said Nilawati, one of those heading several kilometres inland.

Indonesia experiences frequent seismic and volcanic activity due to its position on the Pacific "Ring of Fire", where tectonic plates collide.

Aceh lies on the northern tip of Sumatra island, which is particularly prone to quakes.

In June, a 6.5-magnitude quake struck off the west of Sumatra, damaging scores of buildings and injuring eight people.

A huge undersea earthquake in the Indian Ocean in 2004 triggered a tsunami that engulfed parts of Aceh.

The tsunami killed more than 170,000 people in Indonesia and tens of thousands more in other countries around the Indian Ocean. — AFP