US Air Force B-52 Bombers have been spotted on a secret UK flight amid the on-going Ukraine-Russian war.
It came hours after a spy plane nicknamed Dragon Lady landed at a UK RAF base after completing an unknown mission.
The fearsome American B-52's left people in Glasgow, Scotland, stunned as they looked into the air in the city last night, GlasgowLive reports.
The two US Air Force B-52H Stratofortresses - each with eight engines and weighing 176 tons - were tracked initially over Stornoway around 11.30pm flying one behind the other.
The jets, which flew without call signs, then continued south prior to passing over the Central Belt a short time later at an altitude of some 27,000 feet and at a speed of 428mph.
They were spotted on global flight tracking service Flightradar24 and a person took to Twitter to share news of their appearance in Scottish airspace above Loch Archaig in the Lochaber area north of Fort William.
They tweeted: "A B-52H tearing across Scotland, wish I could see it. I've seen two flying over the Highlands years ago and they were some special", before adding: "Actually two of them".
In operation since the 1950s, the long-range strategic bombers were used during the Cold War for airborne patrols near the Soviet Union to form one component of the US's nuclear deterrent.
On Wednesday afternoon, a spy plane Dragon Lady landed at RAF Fairford in Gloucestershire.
It can fly at an altitude of 70,000 feet, capturing imagery and intercepting signals intelligence, and is said by pilots to be one of the hardest aircraft to fly.
Due to the high altitude it can fly, pilots must wear compression suits, and when landing, rely on a fellow pilot on the ground to guide them as they land on one wheel, reports NorthantsLive.
Although not known if the U-2 spy plane is part of the operation, the mere presence of the aircraft during the ongoing crisis in Ukraine is notable.
However, surveillance aircraft have long been used by both Russia, the US and its allies under the Treaty on Open Skies, an agreement allowing unarmed spy aircraft to conduct missions over the entire territory of member nations.