The head of MI5 has warned that Britain faces a growing threat of terrorist attacks from UK residents trained in Somalia and from dissident Irish republicans.
Jonathan Evans has also made plain that in the Security Service's view the government must maintain special control orders for terror suspects in its forthcoming review of anti-terror laws.
"The government cannot absolve itself of the responsibility to protect its citizens just because the criminal law cannot, in particular circumstances, serve the purposes," Evans said. He added that the potential danger to Britain of extremists influenced by al-Qaida had shifted to Somalia from the tribal areas of Pakistan, which now accounts for half, rather than 75%, of all terror plots linked to Britain.
Evans said "a significant number of UK residents" were training in al-Shabaab camps to fight in the insurgency in Somalia. "I am concerned that it's only a matter of time before we see terrorism on our streets inspired by those who are today fighting alongside al-Shabaab."
UK residents training and fighting in Somalia are thought to number more than 100. They are believed to be of various origins, including Pakistani, Bangladeshi, and west African. MI6, Britain's secret intelligence service, is also increasingly concerned about the spread of al-Qaida inspired jihadists across Africa, according to counter-terrorist officials.
"Al-Shabaab, an Islamist militia in Somalia, is closely aligned with al-Qaida, and Somalia shows many of the characteristics that made Afghanistan so dangerous a seedbed for terrorism in the period before the fall of the Taliban," Evans said.
British officials believe Somalia is now a more serious base for potential attacks on the UK than Yemen where an al-Qaida affiliate developed the "underpants bomb" that failed to blow up an aircraft.
Evans, in his speech yesterday to the Worshipful Company of Security Professionals, in the City of London, also warned of more "signs of co-ordination and co-operation" between dissident republic splinter groups in Northern Ireland. They had mounted or planned 30 attacks so far this year, as against just over 20 for all of 2009, mainly targeted at the security services, he said, describing the dissidents' political base as "small and localised".
Their support is believed to amount to some 600 individuals , including former members of the provisional IRA . The support is less than half that enjoyed by the provisional IRA in its heyday in the 1980s, but members are continuing to be recruited.
Evans also warned of the potential for a terror attack during the 2012 Olympics.
"We should not underestimate the challenge of mounting the games securely in an environment with a high terrorist threat, the first time this has been attempted."
He delivered a clear message to the coalition government and its supporters, who, before the general election, promised to cast away many of Labour's anti-terror laws on the grounds that they threatened civil liberties, saying last night: "The secret nature of this struggle [investigating people suspected of involvement in terrorism] makes it hard for those not directly involved to understand some of the skirmishes that come into the public domain."
He said he preferred to face criticism when there was no prosecution than see a plot come to fruition because MI5 had not acted soon enough.
Nine Britons suspected of having links to terrorism are subject to control orders, the home secretary, Theresa May, confirmed this week.
