A YouTube video allegedly showing bright disc-shaped unidentified flying objects (UFOs) zipping around in the blue skies over central London has emerged as one of the biggest hits online.

The footage visualizes a "mothership" and as around three separate smaller alien spacecrafts looming over the BBC Radio building in West London, Britain.

The video shows the cameraman running towards the corner of Bolsover Street and Clipstone Street in an effort to capture the UFO.

The footage captured by an unidentified UFO enthusiast, also shows how passers-by respond to the UFOs in the sky.

However, there is no dearth of doubters who believe that the video is not authentic. But, one can not confirm the authenticity of the video as the comment box of the clip is disabled. One another video clip of the same UFOs has been uploaded by anonymous YouTube users, called alymc01.

Some people are of the view that that the UFO videos are merely marketing tools to publicize "Iron Sky," the upcoming alien sci-fi movie.