Is anyone else seeing something strange in the London sky tonight? Location: Hackney Central station. Roughly 12:30 - 1:00 AM.

Is anyone else seeing something strange in the London sky tonight? Location: Hackney Central station. Roughly 12:30 - 1:00 AM.
Possible sighting? 

Time: 12:30 - 1:00 AM

Location: London, UK / near Hackney Central station 

At around 12:30/12:40 I was up late working and walked past my living room window facing about 235 degrees southwest. I saw a diagonal band of light, clouds passing over it. It was stationary, fixed, thin, silver/white in colour. I'd never seen anything like this before and continued to stare at it for about 2 minutes. I thought it must be some kind of light  on the ground/from buildings below reflected against the clouds, although it was so bright and seemed to be piercing through the clouds. As soon as I had this thought, the band of light maitained its shape but bounced around across the sky. The band was doing strange somersault-like maneuvers at incredible speed for 5 seconds or less, abruptly stopped, and then remained stationary again for another 3 minutes. My jaw dropped at this point, I am still very confused by what I saw and have never seen something in the sky move like this. At this point, I grabbed my phone; the band of light was still visible to my eye but was not being picked up by the phone. It remained stationary until I could no longer see it. I don't know if it disappeared or if the cloud cover became too thick. I don't see it anymore, have been checking for the last hour.

I am hoping someone else witnessed this too and may have some explanation.