UK intelligence chiefs are warning the country’s government that it is practically impossible to prevent a well-planned terrorist attack. The most likely target for suicide bombers is the upcoming Olympic Games in London.

The report was published on October 9 in the Daily Mail newspaper. According to the paper, MI5 says that the figure of 200 terrorists is a “conservative estimate”. In reality the threat is likely to be much greater.

This information is part of a secret government report on possible threats from Al-Qaeda and other Islamic terrorist organizations. The greatest concern surrounds home-grown terrorists.

Despite the recent killings of such prominent Al-Qaeda leaders as Osama Bin Laden and Anwar Al Awalki, intelligence agencies say that the organization is still strong.

MI5 and MI6 say that terrorists are developing new measures for all new counter-measures. They are more security aware, they know what kind of signs the police will be looking for, and they will avoid things like wearing heavy coats or praying before the attack.

Next year’s Olympic Games will be subject to the UK’s biggest security operation in its history. Security experts believe that terrorists will be unlikely to target the highly-patrolled sporting venues and will target public transport instead.

Another fear is that UK Islamic extremists might adopt the deadly tactic used in other parts of the world and pack explosive vests with shrapnel to harm more victims.

The Daily Mail cites a report that reads reads: 'The internal threat is growing more dangerous because some extremists are conducting non-lethal training without ever leaving the country. Should these extremists then decide to become suicide operatives, intelligence resources, eavesdropping and surveillance would be hard pressed to find them on any radar screen.'

British Islamic terrorists have already carried out suicide bombings, when on 7 July 2005, 52 people were killed and more than 700 injured in attacks on public transport in London.