Two F-15 fighter jets had to apply their afterburners to avoid colliding with two gliders while coming into land at RAF Mildenhall.

The two US Air Force planes were traveling over the Suffolk/Cambridgeshire border at the time of the incident on August 11.

A report from Airprox UK, who review all near-misses over Britain’s skies, deemed the risk of collision to be category B, the second highest rating.

The report heard how the two fighter jets had just been approved to approach RAF Mildenhall in Suffolk when they saw two gliders, the pilots of which are yet to be identified, at less than 150m away.

The F-15 pilots had been informed about a different glider by air traffic controllers at RAF Lakenheath, however, the pilots were unaware of the other two and had to immediately engage max afterburners to climb away and prevent a collision.

The pilots described the risk of collision as "high".

The Airprox UK Board said it was "disappointed" that the two glider pilots could not be traced or had not come forward.

They said it was "unlikely" that the pilots did not see or hear the F-15 which were using max afterburners and were in such close proximity.

Concluding the report, the Airprox UK board said that it was the actions of the F15 pilots, after seeing the gliders late, that prevented a collision.

The Board agreed that the emergency avoiding actions of the F15 pilots was needed to increase the separation and therefore safety was not assured.

They concluded that the incident was risk category B.