They also argued the method, which involves an industrial, full-face mask ... and forced to breathe pure nitrogen gas through ...

COPS are hunting for a "masked man" who reportedly released gas on trams full of passengers ... The suspect was allegedly wearing a face mask underneath a larger industrial mask covering his ...

"I was sat on the tram and a guy got on at Queen's Road wearing a blue face mask with an industrial gas mask over the top of that. Article continues below "There was a hissing noise and people ...