South Korea plane crash: Eyewitnesses report sparks in engine, bird strike; death toll mounts to 127

Witnesses to a deadly plane crash in South Korea's southwestern county of Muan on Sunday reported seeing flames in the jet's engine and hearing explosions as authorities investigate the possibility of landing gear failure from a bird strike.

The Jeju Air flight, carrying 181 people, veered off the runway while landing and collided with a fence wall at Muan International Airport in the Muan County, South Jeolla Province, about 288 kilometres southwest of Seoul, at around 9:07 a.m.

At least 127 people have died while two were rescued, authorities said.

Videos aired by local TV stations show the plane attempting to land without its landing gear deployed. Officials believe the landing gear failure, possibly due to a bird strike, may have caused the accident.

Yoo Jae-yong, 41, who was staying at a rental house near the airport, said he saw a spark on the plane's right wing before the crash, reports Yonhap news agency.

"I was telling my family there was a problem with the plane when I heard a loud explosion," Yoo said.

Another witness, identified only by his last name, Cho, said he was taking a stroll 4.5 kilometres from the airport when the accident took place.

"I saw the plane descending and thought it was about to land when I noticed a flash of light," Cho said. "Then there was a loud bang followed by smoke in the air, and then I heard a series of explosions."

Kim Yong-cheol, 70, said the plane failed to land on the first attempt and had circled back for another before the crash.

Kim recalled he heard the sound of "metallic scraping" twice about five minutes before the crash.

Kim said he looked up at the sky and saw the plane ascending after failing to make a landing before he heard a "loud explosion" and saw "black smoke billowing into the sky."

A 50-year-old witness fishing nearby, identified by his surname Jung, reported seeing a flock of birds colliding with the plane, which triggered a fire in the right engine.

"As the plane was landing on the runway, it hit a flock of birds approaching from the opposite direction," he said. "I heard two or three bangs as if the birds had been sucked into the engine before I saw flames coming from the right engine."

Police and firefighting authorities are conducting an on-site investigation to determine the exact cause.