According to the media, four people suspected of preraring a terrorist attack were arrested Tuesday in a special operation in London.
It was reported that those arrested used to fight in the ranks of the Islamic State organization in Syria.
Media reports run that the terrorist attack was to be perpetrated in a public place.
Earlier, the UK government announced that up to 500 British citizens had left the country to take part in combat actions in the ranks of radical movements, including the Islamic State organization, in Syria and Iraq.
On September 29, the British Defense Ministry reported arresting over 60 Islamic State militants trying to return to the UK from conflict zones.
As of September 30, 25 British nationals planning to take part in combat actions in Syria had been deprived of their passports.
British officials say radical islamists ose a real threat to Great Britain.