SEOUL: Six people have died in a fire in a hotel resort construction site in South Korea's port city of Busan, according to the city's fire agency, with a helicopter used to pluck some 14 people to safety after they had taken refuge on a rooftop.

Around 100 people had been evacuated at the sprawling construction site, where work had been going on in three buildings spanning 12 storeys above ground and three below, the Busan Fire & Disaster Headquarters said.

A Busan fire agency official said on live television that about 25 people had sustained light injuries, including some due to smoke inhalation.

The fire agency said the blaze appeared to have broken out in insulation material loaded near an indoor swimming pool area on the first floor of one of the buildings.

South Korea's Acting President Choi Sang-mok ordered all resources available to be used to extinguish the fire, his office said in a statement.