YouTube pranksters who staged fake robberies at two busy London art galleries, which led to a "stampede" of visitors, have been jailed, the Metropolitan Police said.
Four men appeared at the City of London Magistrates' Court on Monday charged with a public order offence of causing fear and provocation of violence.
On July 5 last year they staged two spoof raids at the National Portrait Gallery and the Tate Gallery in the capital - four of them were arrested on the day of the practical joke.
At around 3.30pm the men burst into the National Portrait Gallery with their faces covered and began shouting and screaming.
CCTV footage captured from the day of the incident shows terrified members of the public fleeing from the National Portrait Gallery in a "stampede".
They gave the impression of a robbery by leaving with fake framed artwork - before repeating the stunt at the Tate Gallery.
Detective Constable Anthony Parker, from the Met's Public Order Crime Team, led the investigation and branded the actions of the men as "outrageous".
He said: "To go into busy public places wearing masks shouting and screaming at a time of heightened awareness of the terrorism threat facing the UK is deplorable.
"The group terrified those visiting the galleries. It is only by pure chance that no-one was injured or suffered serious health issues as they fled in what the judge described as a 'stampede'."
Daniel Raymond Marcus Jarvis, 27, of Turner House, Whitehill Road, Gravesend, Kent, was jailed for 20 weeks for his role in both stunts.
Endrit Ferizolli, 20, of Wakemans Hill Avenue, Brent, was jailed for 16 weeks, and Ebenezer Mensah, 29, of Sumner Road, Peckham and Helder Gomes, 23, of Grantham Road, Lambeth, were jailed for 18 weeks each.
Dan Vahn Lee, 31, of Belham Walk, Southwark, was jailed in March for 12 weeks for his involvement in the National Portrait Gallery incident.
DC Parker added: "All five men now have a number of weeks in jail to consider just how unfunny their stunts actually were."