At least three workers are dead after a bridge collapsed at a highway construction site in Anseong, Gyeonggi Province, some 80 kilometers south of Seoul, on Tuesday.

The fire headquarters of South Chungcheong Province said five other workers were critically injured and one had a minor injury. 

The fire agency believes ten workers were at the site when slabs on the bridge pier collapsed on top of them, and efforts are underway to rescue the one missing worker. 

The agency said earlier that it received a report around 9:50 a.m. about the collapse at the construction site near the section of the Seoul-Sejong expressway where Anseong borders Cheonan, South Chungcheong Province. 

After activating a Level Two response posture, authorities issued an order mobilizing firefighters and national firefighting resources to ensure a comprehensive national response. 

Acting President Choi Sang-mok has ordered related agencies to mobilize all personnel and equipment for rescue efforts and spare no effort to search for the missing worker.