An investigation has been launched after an engine cover fell off an easyJet aircraft seconds after it took off from Milan’s Malpensa airport.

Holidaymakers looked on in horror as the panel broke lose from the engine, the Evening Standard reported yesterday.

Passengers were given a safety briefing as the jet circled for 20 minutes before landing safely, while fire crews gathered below as a precaution.

EasyJet said it was investigating the “technical issue” and would work alongside the relevant safety authorities.

The incident happened on Monday and involved an Airbus A320 bound for Lisbon carrying 174 passengers and six crew onboard.

The aircraft had reached a take-off speed of more than 200mph when the engine cover fell away.

The airport closed for 20 minutes, and following the aircraft’s safe landing the debris was cleared away.

Two incoming flights were diverted during the incident.

In a statement, easyJet said: “EasyJet can confirm that flight EZY2715 from Milan Malpensa Airport to Lisbon on August 12 returned from airborne shortly after take off due to a technical issue with one of the engines.

“The aircraft landed routinely and safely using both engines. All passengers disembarked and easyJet provided an alternative aircraft so they were able to continue their journey to Lisbon later that evening.

“The safety of its passengers and crew is easyJet’s highest priority. We would like to apologise to passengers for any inconvenience experienced due to the delay.”

In May a British Airways aircraft was forced to make an emergency landing at Heathrow after engine covers came loose and caused a fire. A later investigation found the doors had been left unlocked after regular maintenance.