Two F-15 fighter jets had to “take action” to avoid colliding at more than 350mph over Norwich while on their way back to RAF Lakenheath.

The two fighter jets, which were both based in Suffolk as part of the US Air Force’s 48th Fighter Wing, reportedly came within 800ft of each other, according to one of the pilots.

A report released by the UK Airprox Board, which assesses the risk of any close calls in Britain’s skies, concluded that the incident was category B - the second highest rating.

The report said the planes had been involved in a training exercise on October 3, 2019 over East Anglia when the near miss took place.

MORE: Fighter jets in 350mph near miss with skydiversThe first F-15 was in formation with three other planes travelling south-west, heading from the coast over the north-west of Norwich.

At the same time, another F-15 was flying west in a pair to the north of Norwich, but at a lower altitude.

The pilot of the first fighter jet said that the formation had “situational awareness” of the pair and could see them at three and a half miles away.

The pilot said the pair were flying “predictably” in their formation however as they approached, they saw a jet begin to climb.

It then made an “aggressive manoeuvre” to avoid a collision.

At the closest point, roughly over the skies of Cawston, one of the pilots reported the aircraft were only 300ft away. However, the report suggested the real distance was 800ft.

MORE: Meet the Americans living in Suffolk showing their love for the NHSBoth pilots described the risk as “low” however a controller at Swanwick East station said he thought it was “high”.

The controller said he passed traffic information to the second jet on three occasions as they descended towards RAF Lakenheath.

As the two planes became close, the controller issued instruction for the plane to turn to “prevent a possible mid-air collision”.

Concluding the report, the Airprox board said that due to both pilots having to “take action” and that the manoeuvres were “some what last minute”, safety had not been assured.

F-15s from Lakenheath have previously been involved in near misses over East Anglia.

In April last year, two jets travelling at 350mph nearly collided with two parachutists in Cambridgeshire, who caught the footage on GoPro cameras.