The World Health Organization said the Myanmar earthquake was a top-level emergency as it urgently sought $8 million to save lives and prevent disease outbreaks over the next 30 days.

Rescuers braved aftershocks to scour the devastated city of Mandalay for survivors on Monday, after a massive earthquake. In Myanmar, about 1,700 people are confirmed dead so far, about 3,400 injured and around 300 more missing, according to the ruling junta.

At least 18 people have been killed in Bangkok, city authorities said Sunday, with 33 injured and 78 still missing. Across the border in Thailand, rescuers in Bangkok worked Sunday to pluck out survivors trapped when a 30-storey skyscraper that was under construction collapsed after the earthquake.

The earthquake struck northwest of the city of Sagaing in central Myanmar, and was followed by a 6.7-magnitude aftershock minutes later. It destroyed buildings, downed bridges, and buckled roads across the country, with massive destruction seen in Mandalay, the country’s second biggest city and home to more than 1.7 million people.