"It was like the apocalypse," the 39-year-old said, as he recalled seeing the fire tear through the area, which, even before the inferno struck, had been suffering from a particularly dry spell.

"The mountain burning looked like literal hell," he added.

Tens of thousands of people in the southeast had to evacuate from the wildfires, which have been burning continuously for five days, fanned by high winds and fuelled by the super-dry conditions.

Sections of National Route 7, the main east coast highway, descended into chaos as the fires caught up with evacuees stuck in traffic jams, struggling to escape.

"Fireballs rained down like rain between the jammed vehicles, setting cars on fire," one eyewitness told local media.

"Drivers barely escaped from the burning cars - it was utter chaos."

Apple farmer Cho Jae-oak, 75, who fled from his property, told AFP that he also saw fireballs flying down from the mountain.

He and his wife had sprayed water to try and save their farm but were eventually forced to escape.

At least 24 people have been killed so far, some of whom died during the evacuation process, the Korea Forest Service said.

The country's acting president, Han Duck-soo, said the multiple fires had caused "unprecedented damage" and warned it could still get worse.

The strong winds -- plus a crash, killing a pilot -- have forced authorities to suspend helicopter and drone operations to battle the blazes, which are straining conventional firefighting capacity, officials said.

- Evacuate! -

"Attention Hawmaeri residents. Please evacuate quickly!" yelled the village chief.

"The entire village is on fire, and your house will catch fire soon."

A heart wrenching video circulating online and verified by AFP showed the village chief of Hawmaeri, home to around 46 households, urging residents to flee as the Uiseong fire barrelled towards their homes.

Most of the villagers escaped, but officials later confirmed that the village chief and his family were found dead on Tuesday, next to their burned-out car.

The car was heading the opposite direction from evacuees, local police told reporters.

Locals said the family had been "trying to rescue residents who might have been isolated".

Most of the deaths were residents, but at least three firefighters were killed, and a helicopter pilot, who died when his aircraft crashed in a mountain area, officials said.

There are also reports of missing people, officials say, including one woman in her 80s who was suffering from dementia.

In addition to thousands of firefighters, backed up by soldiers and other emergency staff, rescue workers have been heading to the southeast to assist around 27,000 evacuees.

Animal rescue organisations have also rushed to the area, as many dogs in rural South Korea are kept tied up outside, with local media reporting that dozens of animals had died from smoke inhalation.

The groups reported finding dogs that survived, trembling in fear with severe burns.

- Shock and anger -

Inside an evacuation shelter in Andong, a quiet elementary school gym now filled with mostly elderly residents, the air was silent and heavy with shock.

South Korea's demographic crisis -- it is a super-aged society with the world's lowest birth rate -- was also on full display.

The average age in many villages exceeds 60, officials have said.

Most of the evacuees were elderly and AFP reporters saw medics handing out medicine to those who had fled too quickly to bring what they need to manage chronic illnesses.

Officials told reporters that most of the dead were in their sixties to seventies.

Many evacuees at the shelter voiced not only shock but frustration, saying their homes had been burned before fire fighters showed up.

The fire was reportedly started by someone tending an ancestral grave site, who then called emergency services saying they had accidentally triggered the conflagration.

"It's not a problem who started the fire, but this entire region needs to cooperate with the country to put out this fire. We need to put out the fire quickly," Park Sung-tae, farmer told AFP.

He said he was concerned that if the smoke blocked out the sunlight for too long, this year's crop would be lost.

"It will make farming difficult," he added.