A fire has ripped through a hotel in South Korea, leaving at least seven people dead and a dozen injured as guests desperately tried to escape the inferno.

Some of those who perished had jumped from the eighth floor down onto air mattresses below, local media reports.

It wasn’t immediately clear what caused the blaze, which officials said began on the eighth floor of the nine-storey hotel in the city of Bucheon just after 7.30pm.

Firefighters were able to prevent the flames from spreading throughout the building, however thick black smoke is reported to have filled multiple floors, causing a number of the casualties. 

Emergency workers said they found some victims scattered through halls and stairways, likely caught by the smoke as they tried to flee. Foreign nationals are thought to be among the dead.

Kim In-jae, the director of Bucheon’s public health department, said in a briefing that three of the victims who were injured were in serious condition. 

According to officials, the hotel is a reinforced concrete building with two underground floors and nine above-ground floors.

It has 64 guest rooms, and there were 27 guests staying at the time of the fire, most of whom were reportedly in rooms on the seventh to ninth floors. 

A 40-year-old guest named only as Seo told local media: ‘The alarm sounded and I heard screams, so I came out without even being able to collect my luggage.’

He claimed that ‘the sprinklers did not work and there was no one to guide me.’ 

A fire official said, ‘When we arrived at the scene, it was already filled with smoke, so it took a long time to put out the fire, and many of the guestroom doors were locked, so it was difficult to rescue the guests.’ 

Most of the seven guests who died in the fire were found in the stairwells and hallways between the eighth and ninth floors of the hotel, Korean media reports.

Three other guests were seriously injured and nine suffered less serious injuries, with the wounded transferred to six nearby hospitals.

The fire was extinguished at 10.26pm, about three hours after it broke out, authorities said.

But they warned that there may yet be more casualties as the search of the rooms continues.

More than 150 firefighters and 46 vehicles were deployed to put out the blaze and scour the corridors and rooms of the hotel for survivors.