Video on YouTube.
The ceremony took place in the sleeping area of the city, in the southeastern part of Kazan. There are no factories and industrial complexes nearby. The sound lasted about 5 minutes. The source of the sound came from everywhere; it was as if a giant metal was hovering under the ground or in the sky, I had never heard anything like that.

And the comments:
This is the alarm of Chuck Norris.

the variant of alkas with the pipe still in force? )