A powerful earthquake centred in Myanmar has killed more than 150 people in the war-torn country and neighbouring Thailand and caused widespread damage.

Here is what we know:

Powerful and shallow

The 7.7-magnitude quake hit northwest of Myanmar's Sagaing at 12:50 PM (0650 GMT, 11:50 PM PHT) on Friday at a shallow depth of 10 km. (six miles).

It was followed minutes later by a powerful 6.7-magnitude aftershock and a dozen smaller tremors.

The quake was felt across the region, with shaking reported from India to the west and China to the east, as well as, Cambodia and Laos.

The quake hit along the Sagaing Fault that runs from the coast to Myanmar's northern border, according to earthquake scientists Judith Hubbard and Kyle Bradley.

It "has long been considered one of the most dangerous strike-slip faults on Earth" because of its proximity to major cities Yangon and Mandalay, as well as capital Naypyidaw, they wrote in an analysis.

The fault is comparatively simple and straight, which geologists believe can lead to especially large quakes, they added.

Over 150 killed

At least 144 people have been confirmed dead in the quake in Myanmar, according to the country's junta chief.

However, Min Aung Hlaing warned the toll was likely to rise given the widespread destruction across the country.

Myanmar's four years of civil war, sparked by the military seizing power, have also weakened the country's emergency and health services, leaving them ill-equipped to respond to such a disaster.

In Thailand, 10 people were killed in Bangkok, most in the collapse of an under-construction skyscraper.

But up to 100 more construction workers were believed trapped in the rubble of the building, near the sprawling Chatuchak market.

Rescue operations continued throughout the night, though it was proving complicated to pick through the unstable rubble.

Widespread damage

The quake caused extensive damage in Myanmar.

There was massive destruction in Mandalay, where multiple buildings collapsed into piles of rubble and twisted metal coated in dust, dotted with people attempting rescues.

The Ava bridge running across the Irawaddy river from Sagaing, built nearly 100 years ago, collapsed into the swirling waters below.

There were reports of damage to Mandalay airport, potentially complicating relief efforts, as well as to the city's university and palace, according to the International Federation of Red Cross and Red Crescent Societies.

In Naypyidaw, AFP reporters saw buildings toppled and roads ruptured.

At a hospital in the capital, patients were being treated outdoors after the quake damaged the building, bringing down the emergency department's entrance.

Electricity outages were reported in several places, with power limited to four hours in Yangon due to quake damage.

Communications across affected areas were also patchy, with phone networks largely down.

In Bangkok, a crane collapsed at a second building site, and the city shut down metro and light rail services overnight to inspect for damage.

Several hundred people slept in parks overnight, city authorities said, either unable to get home or worried about the structural integrity of their buildings.

The quake prompted thousands of people to flee shaking buildings in Thailand, where quakes are rare.

Even hospitals were evacuated, with one woman delivering a baby in the street in Bangkok, and a surgeon continuing to operate on a patient after being forced to leave the theatre mid-operation.

Aid pleas, offers

The scale of the devastation prompted Myanmar's isolated military regime to make a rare plea for international assistance.

Myanmar's junta chief invited "any country, any organization" to help with relief and said he he "opened all ways for foreign aid."

Offers of assistance flooded in, with neighbour India among the first to say it was ready to help.

The European Union offered support, and US President Donald Trump said Washington had "already spoken" with Myanmar about aid.

"It's a real bad one, and we will be helping," he told reporters.

The World Health Organization said it was preparing to surge support in response to "a very, very big threat to life and health."