Claim: A video shows an emergency alert siren playing in public in London.
Fact-check: This video does not show an official alert siren playing in London - Full Fact
Verdict: it is very unlikely this happened. the uk's civil defence siren has been retired since 1992, and most of the actual siren systems removed. we could find no other coverage of a siren playing in the area shown in the clip.
Organisation: Full Fact
Author: Rachael Krishna
Date published: 2020-01-09T00:00:00