An interior ministry official told AFP that the injured were being transported to hospitals.
The incident took place at around 9.50am (8.50am, Singapore time) in Anseong, around 65km south of the South Korean capital.
Authorities had initially said it took place in the nearby city of Cheonan, but later corrected that claim.
Five 50m steel structures supporting the highway bridge collapsed one after another after being hoisted into place by a crane, the Yonhap news agency reported.
Acting President Choi Sang-mok has issued urgent directives to mobilise all available resources and personnel for the rescue operation.
According to data from Seoul’s labour ministry, more than 8,000 work-related deaths occurred in the country from 2020 to 2023.
Source: CNA
