More than 300 passengers and crew members were evacuated from a Korean Air plane, as fire broke out on its left-side engine just before taking off from a Tokyo airport on Friday.

The Boeing 777-300 jet was speeding up on the runway of Haneda Airport for departure but suspended its operation immediately after a spark was detected at 12:20 p.m. on its No.1 engine on its left-wing, a Korean Air official said.

The flight was heading for Seoul, with 302 passengers and 17 crewmembers onboard.

They were evacuated safely through emergency chutes, the air carrier said. Seoul’s Foreign Ministry said that there were no reports of injuries as of 3:00 p.m.

But local reports quoting a Japanese official said there were unconfirmed reports that two men and five women were injured.

More than 100 firefighters and rescue workers put out the blaze within an hour. The runway the jet was moving down has been closed. All other flights have been halted for safety.

Korean Air said it sent a special flight later in the afternoon to bring back the passengers, calling it an urgent priority for the air carrier. The returning flight was set to return at 6:00 p.m. to Gimpo International Airport, near Seoul.

The exact cause of the engine fire, however, was unknown, the company said. The Japanese authorities are set to investigate the case, with Seoul dispatching officials from the transport and foreign ministries.

“The flight has been operating for 15 years but we can’t say that the cause of the fire is simply related to possible deterioration, as the last time we replaced the engine component was in 2014,” an official told The Korea Herald.

The Japanese police said the fire did not appear to have been caused by an act of terrorism, with some suggesting the possibility as Japan was hosting the G7 leaders’ summit.

When asked about the compensation process for passengers claiming their inconvenience, he said Korean Air will come up with plans in compliance with international aviation law.

By Cho Chung-un, news reports (christory@heraldcorp.com)