What you don't want to see when you look out the window of your plane - air force fighter jets

Passenger Emily Hatfield snapped this photo of a fighter jet shadowing the flight. Photo / Twitter

The last thing you want to see when you look out the window of your plane is an air force fighter jet on your tail.

But that's exactly what terrified passengers on board a flight from Spain to Britain spotted overnight, sparking panic on board the budget airline, said news.com.au.

Jet2 flight 1204, a Boeing 737-800, was part-way through its journey from the tourist hotspot of Malaga to Birmingham when it passed through French air space.

That's when two Mirage 2000 fighter jets suddenly appeared and shadowed the aircraft for more than 15 minutes, AirLive reported.

Passengers on board the Jet2 flight from Spain to Britain were nervous about two French air force fighter jets tailing their plane. Photo / Flickr

Passenger Sarah Hatfield told the BBC that one of the jets was so close she could read the writing on its tailfin. Her daughter Emily took a picture on her mobile phone.

Cabin crew were alerted and they informed the pilot. It was eventually announced that there was nothing to worry about, Ms Hatfield said.

But she described the mood on board as "a mixture of excitement at seeing the fighter so close up and terror as to if we were about to get shot down".

The incident, Saturday afternoon local time, came on the back of deadly terror attacks in Spain.

NEWS Tourists ‘terrified’ as Jet2 flight from Malaga is tailed by French fighter jet https://t.co/spD1CO4XaK pic.twitter.com/bNJDbxp3XD

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"(My husband) was terrified and it didn't help that loads of other passengers came by us to look out at it," she said.

A Jet2 spokesperson told BBC it was investigating the issue.

"We are awaiting clarification from the French air traffic authorities as to why a military aircraft was apparently tracking our aircraft."

However AirLive quoted the French air force as saying the Jet2 plane was "intercepted due to loss of communication".