The accident happened about two hours after takeoff on an aircraft operated by Malaysian budget carrier AirAsia that was on its way to Hong Kong from Malaysia.

It was a backup battery that exploded, badly burning the 26-year-old Chinese owner of the phone, the management board of Tan Son Nhat International Airport stated Thursday.

As soon as the plane landed an ambulance rushed the passenger to the Cho Ray Hospital, about 8 km away.

Doctors said the victim had suffered 20 percent burns, mostly in his left arm, left leg, left buttocks and the back of the left thigh. After treatment, his health was stable and he was discharged from the hospital Thursday.

The flight was delayed for many hours and only took off from the Tan Son Nhat airport on 10 a.m. Thursday, touching down in Hong Kong at 1:21 p.m. (local time).

Passengers are allowed to carry a backup phone charger in their carry-on luggage, but not in checked bags. When a flight takes off or lands, the crew remind passengers not to use electronic devices to ensure safety.

The Civil Aviation Authority of Vietnam is investigating the incident to ascertain more details.