Four men are being questioned by British anti-terror police after being arrested in and around London.
The BBC reports that the men, aged between 19 and 27, were all taken to police stations in central London after their arrests overnight and remain in custody.
They were arrested on suspicion of being involved in a plot by radical Islamists - which some London tabloid newspapers have described as a possible attack on the Queen.
According to the reports, the men, aged between 19 and 27, were planning to stab the Queen while she attended World War I anniversary events.
Police said one of the men was arrested in a car in a street in Southall, with armed officers assisting, but no shots were fired.
