London law enforcement wrote about this on their Twitter page.
“The man was detained on Parliament Square at about 10:45 (12:45 Moscow time) after he poured himself, presumably, with a combustible liquid. There are no victims, ”the statement said.
It is clarified that he was able to pour liquid on himself and get a lighter, but did not have time to set himself on fire, as he was immediately doused with fire extinguishers and detained by the police.
The reasons for his action are not yet known.