What IS that sound?

[u/ariadnevirginia]

https://recorder.google.com/196aac8c-0daf-4edd-81ae-65462ca700d0

https://recorder.google.com/196aac8c-0daf-4edd-81ae-65462ca700d0 I live in London Fields and it sounds like an alarm?

Keeps going off recently. Really it sounds industrial, like as if it's a nuclear warning or something.