An Asiana Airlines cargo plane carrying two people crashed into waters off South Korea's southern resort island of Jeju today, an airline official said.
The plane crashed after reporting a mechanical problem and losing contact with air traffic workers, airline official Kim Dong-won said.
Five coast guard patrol boats and four helicopters were searching the area for signs of the pilot and co-pilot, Jeju coast guard spokesman Choi Kyu-mo said.
Coast guard searchers have recovered part of a wing with an Asiana Airlines logo on it, life jackets and parts of a pilot seat, the coast guard said in a statement.
The plane had taken off from South Korea's Incheon International Airport, west of Seoul, and was bound for Pudong in China, Asian Airlines said in a statement. It was carrying computers, semi-conductors, paint and resin solution among others, it said.
Asiana officials got a report early today from the pilot that the Boeing 747, which was south west of Jeju, was having mechanical difficulties and would try to make its way to the island's airport, said Jason Kim, a spokesman for Asiana.
Officials then lost contact with the plane and asked the South Korean coast guard to investigate, Mr Kim said. The airline also sent its own emergency specialists to the area.
South Korea has been lashed with extraordinarily heavy rain this week, with landslides and floods killing dozens and causing havoc. Mr Kim said it was unclear whether the weather had caused any problems for the plane.
Coast guard officials said there was no rain in the area but stronger-than-normal wind.
Asiana Airlines was in the news last month when two South Korean marines fired rifles at an Asiana plane carrying 119 people. South Korea's military later apologised, saying the marines mistook the plane for a North Korean military aircraft.