Nigeria’s Accident Investigation Bureau (AIB) has started investigating an incident where an engine of a Delta Airline aircraft caught fire mid-air.

Delta Air Flight DAL55 involving an Airbus aircraft departed from Lagos, Nigeria, to Atlanta, Georgia, US, on Tuesday when the incident occurred.

It prompted the aircraft to return to the Lagos International Airport for an emergency landing within less than an hour after commencing its journey.

“We look forward to receiving cooperation from Delta Airlines as we work to determine the cause of this serious incident in the interest of safety.”

All onboard passengers and crew exited the aircraft on the runway through emergency slides.

Five passengers reportedly sustained non-critical injuries because of the evacuation at the airport, but Delta denies any such report.

According to Nigerian Civil Aviation Authority (NCAA), the injured passengers were rushed to Lagos State University Teaching Hospital (LASUTH) for medical care.

AIB commissioner Akin Olateru was quoted by punchng.com as saying: “We look forward to receiving cooperation from Delta Airlines as we work to determine the cause of this serious incident in the interest of safety.”

AIB has accused Delta of not reporting the incident earlier to the bureau.

However, the airline has apologised to AIB for the incident, when a team of its officials visited Lagos following the accident.

The US National Transportation Safety Board (NTSB) is also looking into the accident, along with AIB.