An Air China flight from Hangzhou to Seoul was forced to make an emergency diversion to Shanghai on Saturday after a lithium battery inside a passenger’s carry-on bag caught fire mid-air, Gulf News reported.

According to Air China, the fire broke out in an overhead compartment on flight CA139. The cabin crew acted swiftly to extinguish the flames, preventing any injuries or major damage.

The aircraft took off from Hangzhou at 9.47am local time and landed safely at Shanghai Pudong International Airport shortly after 11.00am, the airline confirmed.

Images shared by Chinese media outlet Jimu News showed flames and smoke rising from the cabin’s upper section, while one passenger was seen assisting the crew in putting out the fire.

Flight-tracking website Flightradar24 showed the aircraft making a U-turn over the sea before returning to China.

Air China said an investigation is underway, stressing that passenger safety remains its top priority.