In a rare public speech on Monday, MI5 director-general Jonathan Evans though dispelled fears saying, "The Games are not an easy target and the fact that we have disrupted multiple terrorist plots here and abroad in recent years demonstrates that the UK as a whole is not an easy target for terrorism."
Promising a "successful and memorable Games this summer in London" , he said, "We are far from complacent. A lot of hard work still lies ahead and there is no such thing as guaranteed security."
MI5 and other counter-terriorism agencies have prevented major incidents on British soil other than suicide missions on London's underground in 2005.
Methods and tactics of combating Islamic terrorism had improved over the years. "You could say that we are near to reaching a form of stalemate — they haven't stopped trying but we have got better at stopping them," he said.
Evans warned of a new threat emerging from an "Arab world in radical transition" . The terror outfit, al-qaida , has taken advantage of instability in the region after last year's Arab Spring.
They have regrouped in the region after feeling threatened by Nato forces in Afganistan , he said. Revolutions towards democracy in Arab countries offered hope, but there was a "more immediate problem" as al-Qaida has returned to its original habitat.
Scores of would-be British jihadis are travelling to Arab countries to be trained by al-Qaida. They are currently being trained in Libya, Egypt, Yemen and Somalia, Evans said. Figures last year suggested more than 100 Britons were absorbed by terror groups in Somalia.
It is suspected that many are now being prepared for terrorist attacks across Yemen , Egypt and Libya. Evans also suggested there could be a steady stream of new recruits from the UK. From a British domestic perspective, Evans said, "Some will return to the UK and pose a threat here. This is a new and worrying development." Speaking about the threat perception in Britain, he said, "In back rooms, in cars and on the streets of this country there is no shortage of individuals talking about wanting to mount terrorist attacks here."
Edited By Cen Fox Post Team
