Footage shows a road snapped into pieces by an earthquake that struck Myanmar today, causing devastation across Southeast Asia.

The highway on the outskirts of Mandalay buckled and crumbled as the tremors battered the region.

The US Geological Survey said the 7.7 magnitude earthquake struck at a depth of 10 kilometres (six miles), and was centred in Myanmar, around 50 kilometres (30 miles) east of Monywa City.

There were a number of aftershocks, with tremors felt across Southeast Asia. Thousands are feared to have been killed.

Earthquake monitors said a shallow tremor struck central Myanmar at 13.20 local time (6.50 GMT), and was followed minutes later by a 6.4 magnitude aftershock.

Officials at a major hospital in Naypyidaw, the capital, declared it a 'mass casualty area', with the death toll expected to rise after buildings fell and debris scattered.

In Thailand, a high-rise apartment block that was being built in the Chatuchak district of the city collapsed, burying dozens of workers in the debris. At least four were killed.

Thai Prime Minister Paetongtarn Shinawatra declared Bangkok an emergency zone as the quake wrought carnage across the capital city.

Earthquake rescue efforts are ongoing in Thailand and Myanmar.