An Asiana Airlines-operated aircraft has crash landed at San Francisco international airport, killing at least two people.

The Boeing 777 made an emergency landing earlier, after arriving from Seoul.

The airline told reporters mechanical problems did not cause the crash.

“Currently we understand that there were no engine or mechanical problems,” Asiana chief executive Yoon Young-Doo said during in a briefing in Seoul.

Eyewitness accounts suggest the plane came in too short and hit the seawall at the airport.

There were 291 passengers and 16 crew on board, Asiana said.

Asiana is South Korea’s second-largest airline.