Mar 28, Kathmandu- A 30-story government office building under construction in Bangkok collapsed after a powerful 7.7-magnitude earthquake struck Myanmar on Friday, trapping 43 workers, police and medics said.

The building, located in the northern part of the Thai capital, was reduced to a tangle of rubble and metal in seconds.

A 7.7-magnitude earthquake struck northwest of Sagaing city on Friday afternoon, the US Geological Survey said. A 6.4-magnitude earthquake struck the same area minutes later.

Meanwhile, Thai authorities have declared a state of emergency in Bangkok. Prime Minister Shinawatra announced the state of emergency on Friday after a powerful earthquake centered in Myanmar hit the city.

Several buildings in Bangkok were reported to have been damaged by the quake, including a 30-story under-construction building in the northern part of the city that collapsed.