The death toll has risen to six after a fire broke out at a resort construction site in the South Korean city of Busan, local media reported on Friday.

About 100 workers managed to evacuate from the site and about 90 firefighters were trying to put out the blaze, which was reported at around 10:20 a.m., according to Busan’s fire agency.

It wasn’t immediately clear whether workers were still trapped inside.

Four people sustained minor injuries.

Television footage showed gray-black smoke and flames rising from the site and a helicopter approaching the building as part of rescue efforts.

The country's acting president, Choi Sang-mok, instructed officials to deploy “all available personnel and equipment” to extinguish the fire.