The spillway of Swar Chaung dam overflowed and collapsed around seven in the morning, affecting the nearby areas including the country's busiest highway and some towns in the Bago region, Xinhua news agency reported.
The Swar Chaung bridge has also been closed as it was damaged by the flooding, Ministry of Construction said in a statement.
People in the affected areas are being evacuated to safer places and efforts are being made to resume the transport link in the area.
The Yangon-Mandalay Expressway connects the country's largest city Yangon and second largest city Mandalay. The highway, which does not meet international design, construction and safety standards, has seen a spate of accidents since its opening in 2010.
(This story has not been edited by Social News XYZ staff and is auto-generated from a syndicated feed.)
