A Frankfurt-bound passenger jet of Asiana Airlines Inc., South Korea's second-ranked flag carrier, has flied back due to an unidentified engine problem, the company said Sunday.

The B747-400 plane carrying 340 passengers took off at 12:34 a.m. on Saturday but returned to Incheon International Airport at 3:10 p.m.

The return decision was made as pilots discovered an engine malfunction warning just 30 minutes after its takeoff. It had to stay in air to let remaining fuel out.

No injuries or damage were reported.

The passengers had to stay in a nearby hotel before leaving for Frankfurt, Germany at 9 a.m. on Sunday, Asiana Airlines said.

Due to the delay, around 600 passengers suffered inconvenience including the 344 passengers scheduled to travel on the same plane from Frankfurt to Incheon. (Yonhap)