Rescuers scrabbled through the rubble of shattered homes, shops and mosques in search of survivors Wednesday after a powerful earthquake struck western Indonesia and killed at least 97 people.

The shallow 6.5-magnitude quake struck Aceh province, one of the areas worst affected by the devastating 2004 tsunami, at dawn as many in the mainly Muslim region on Sumatra island were preparing for morning prayers.

"So far 97 people have been killed and the number keeps growing," Aceh military chief Tatang Sulaiman told AFP after the army took over responsibility for the search and rescue.

"When we retrieve bodies sometimes there's five, sometimes 10 corpses."

More than 1,000 soldiers and about 900 police have been deployed to Pidie Jaya district to set up shelters and evacuation points in the worst-hit areas, he added.

Rescuers used excavators and their bare hands to comb the wreckage for people still missing.

Hundreds of houses and shops were levelled by the quake, leaving countless people homeless and in need of basic supplies like food and water, officials said.

"The electricity is still off. Some places have generators, but there are not many," local disaster agency head Puteh Manaf told AFP.

"If it rains there will be disease."

- 'Everything was destroyed' -

The sole hospital in Pidie Jaya was quickly overwhelmed, with patients treated on the grass out front or sent to neighbouring districts with better facilities.

The district health office chief Said Abdullah said nearly 200 injured had arrived since the quake, but many would not enter the hospital for fear of aftershocks.

"We are treating people outside. We took the beds out because nobody is daring to enter the hospital," he told AFP.

Another regional hospital had suffered serious damage in the quake, along with schools and other key infrastructure, a national disaster agency spokesman said.

In the hard-hit town of Meureudu, terrified residents rushed outside as their homes buckled and crumbled.

"Everything was destroyed," said Hasbi Jaya, who pulled his two children unconscious from the rubble of their home.

"It was pitch black because the electricity was out. I looked around and all my neighbours' homes were completely flattened."

An AFP correspondent said dazed residents were wandering debris-strewn streets, unable to return to their damaged homes in fear of aftershocks.

Some fled to higher ground for fear of a tsunami although no alert was issued.

A huge undersea earthquake in 2004 triggered a tsunami that engulfed several countries around the Indian Ocean, killing more than 170,000 people in Indonesia alone, the vast majority in Aceh.

Indonesian seismologists said the latest earthquake was felt across much of Aceh province, with many aftershocks following the initial tremor.

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

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.

Major Indonesian quakes
Jakarta (AFP) Dec 7, 2016 - A powerful 6.5-magnitude quake struck off Aceh province on Indonesia's Sumatra island Wednesday, killing at least 97 people as rescue workers continued to pull more bodies from the rubble of scores of shattered buildings .

Here is a chronology of the largest quakes to hit Indonesia in recent years:

- December 26, 2004: A massive earthquake measuring 9.1 on the open-ended Richter scale strikes off the coast of Sumatra and triggers a tsunami that kills 170,000 people in Indonesia, and more than 220,000 throughout the region. It is the world's third biggest quake since 1900, and lifts the ocean floor in some places by 15 metres (50 feet). The province of Aceh is the hardest hit area, but the tsunami affects coasts as far away as Africa.

- March 28, 2005: A quake measuring 8.7 strikes off the coast of Sumatra, killing 900 people and injuring 6,000. It causes widespread destruction on the western island of Nias.

- May 27, 2006: A 6.3-magnitude quake rocks a densely populated region of Java near the city of Yogyakarta, killing 6,000 people and injuring 50,000. Some 330,000 houses and 12,000 schools are either destroyed or damaged.

- July 17, 2006: An offshore earthquake measuring 7.7 triggers a tsunami that hits the southwestern coast of Java near the resort of Pangandaran, killing more than 600 people.

- September 2, 2009: More than 100 people die when Java is hit by a 7.0-magnitude quake.

- September 30, 2009: A 7.6-magnitude quake hits Padang, a major port on the west coast of Sumatra, killing around 1,000 people. Almost a half million others are left homeless after some 100,000 homes are destroyed.

- October 25, 2010: More than 430 people die when a 7.7-magnitude quake and a tsunami hits the isolated region of Mentawai, off the coast of Sumatra. Several villages are destroyed by waves more than three metres (10 feet) high which extend up to 600 metres (yards) inland. Around 15,000 people are left homeless.