At least 167 people are confirmed dead and just two people - both flight crew - were rescued, South Korea's fire agency said, after a Jeju Air plane crashed on landing with 181 people on board.
The flight from Bangkok crashed on landing at Muan Airport - before hitting a wall and bursting into flames.
So far, just two crew members were rescued from the tail section of the burning plane.
There've been reports the landing gear of the Boeing 737 malfunctioned.
A collision with birds and adverse weather conditions were cited by the authorities as likely causes of the crash that flung passengers out of the plane and left it "almost completely destroyed", according to fire officials.
Video showed the Jeju Air plane landing on its belly without wheels at Muan International Airport, skidding off the runway as smoke streamed out from the engines, before crashing into a wall and exploding in flames.
"Passengers were ejected from the aircraft after it collided with the barrier, leaving little chance of survival," a local fire official told families at a briefing, according to a statement released by the fire brigade.
"The plane is almost completely destroyed, and identifying the deceased is proving difficult. The process is taking time as we locate and recover the remains," he was quoted as saying.
A photo showed the tail section of the plane - a Boeing 737-8AS according to Flight Radar - engulfed in flames on what appeared to be the side of the runway, with firefighters and emergency vehicles nearby.
The Muan International Airport is in Muan county, which is about 288km southwest of Seoul.
The fire agency said it had mobilised 32 fire engines and scores of fire fighters to the scene.
The Ministry of Land said that a "total of 175 passengers - including two Thai nationals - and six crew members were onboard."
The initial fire was extinguished and a search and rescue operation was "under way at the crash site", it said in a statement.
Acting President Choi Sang-mok called for the mobilisation of all resources to save the passengers.
"All related agencies... must mobilise all available resources to save the personnel," he instructed officials in a statement.
Mr Choi convened an emergency meeting with cabinet members to discuss rescue operations and response before heading to Muan, his office said.
