Two people were killed and seven injured after a bridge collapsed at an expressway construction site in South Korea on Tuesday, authorities said.

Local media aired dramatic footage of what appeared to be a section of the bridge collapsing, sending a massive cloud of smoke into the air.

Two people died, six were seriously injured and one suffered a minor injury, according to a statement from the National Fire Agency.

Authorities are still searching for one person, the agency said.

An interior ministry official told AFP that the injured were being transported to hospitals.

The incident took place at around 9:50 am in Anseong, around 65 kilometres (40 miles) south of the South Korean capital.

Authorities had initially said it took place in the nearby city of Cheonan, but later corrected that claim.

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.