The moment a plane passenger spotted a 'UFO' through the window as it flew over London has been caught on camera.
The footage, which appears to show a disc with lights on either side flying over the cloud line,was caught on video on the morning of 25 May, while the plane was flying over the capital, reports the Mirror.
There was a mixed reaction from YouTube users, with one writing: "Very convincing."
However, most people don't think it was some kind of alien invasion. One user wrote: "Why did they photoshop an oiler ship into the sky?"
Another wrote: "That is obviously a swamp gas or a weather balloon... and if it is indeed an unidentified flying object - then it would be an experimental aircraft or some sort or another."
It's not the only 'UFO' spotted in the skies over London recently. Back in April, a bizarre object was spotted in the sky over London and pictures were uploaded to the Mixtris UFO images page on Facebook titled, 'Strange object in the sky over North London'.
And, back in January, a passenger plane was involved in a near-miss with a UFO while flying near Heathrow Airport.
The pilot of the jet reported a 'rugby-ball'-shaped UFO passing within a few feet of the plane, the Daily Telegraph reports.
Is it a bird? Is it a plane? Are aliens landing in London? What do you think the latest sighting could be? Leave your thoughts below.