The United States Airforce has revealed why a B-2 stealth bomber was seen soaring over Ipswich.

The incredible plane was seen flying low over much of Ipswich and south Suffolk yesterday evening, and caused an instant reaction on social media.Those lucky enough to catch a sighting included residents believing they had seen a UFO, while others gazed in awe as the famous heavy bomber ripped through the Suffolk skies.Normally based in their home at Whiteman Air Force Base in Missouri, USA, the 509th Bomb Wing and their stealth bomber are currently stationed at RAF Fairford in Gloucestershire.The airfield is currently the Americans' only European base for heavy bombers.Announcing the deployment's arrival in late August, the air force said the fleet will be training in the UK with other US units to increase readiness and build on strategic relationships in order to confront global challenges.The unit has already made headlines across the country with their exercises, having previously being spotted in Norfolk two weeks ago, while also taking part in a refueling exercise at Lajes Field in the Azores. On August 28, it flew to Keflavik Air Base in Iceland for the very first time.MORE: Did you see the stealth bombers flying low over Suffolk?

Closer to home on August 30, two of the bombers were seen flying over the White Cliffs of Dover alongside two RAF F-35 jets.

General Jeff Harrigian, commander of US Air Forces in Europe and Air Forces Africa, said: "Bomber Task Force missions provide us an opportunity to train and integrate with our allies and partners in the region.

"When we bring bombers like the B-2 into theatre, they deliver a measure of deterrence and enhance our ability to develop our overall readiness, our posture and further increase our partnerships across the globe."

First built as a prototype nuclear bomber in 1987, the Northrop Grumman B-2 Spirit - to give its full name - it earned the nickname "stealth bomber" thanks to being able to remain undetected by sophisticated anti-aircraft defence systems.

It is estimated that each unit costs a whopping $2.1billion, with 21 of the distinctive aircraft being built since their introduction to military service in 1997.

Today, 20 remain in service although they are planned to retire in 2032.