The Syrian civil war is breeding a new generation of terrorist In towns such as Raqqa that are now under the control of Islamist militias, inhabitants claim they have suffered severe beatings for committing minor transgressions, such as spraying graffiti, while women have been banned from visiting male doctors. Captured pro-Assad fighters, meanwhile, are regularly beheaded in public. So it is hardly surprising that the presence of hundreds of Western volunteers within the ranks of the Syrian opposition movement is increasingly viewed with grave concern by security officials, who fear the conflict is being turned into a fertile breeding ground for a new generation of Islamist terrorists. This is particularly true in this country, where British intelligence estimates that more than 300 British Muslims are now actively engaged in fighting for al-Qaeda-linked groups, such as the Nusra Front. Scotland Yard warned yesterday that London was facing a "disturbing" new threat, with jihadists as young as 16 travelling to take up arms in the Syrian conflict. Richard Walton, the head of counter-terrorism command, warned there were signs of returnees being ordered by militants associated with al-Qaeda to carry out attacks in Britain. Nor is the threat confined to the UK. Hundreds of radicalised young Muslims are reported to have made their way to Syria from other Western nations, such as the US, Canada and France, while intelligence officials have been surprised at the large number of Australian nationals - estimated at around 200 - who have travelled halfway round the world to fight. This new wave of Western jihadists has been inspired by the increasingly sophisticated recruitment techniques used by Islamists to lure them to the eastern Mediterranean. British extremists have recently taken to posting their exploits on social media networks, with one activist describing the fighting in Syria as "5-star" jihad because of the relaxing nature of the conflict, while another posted images showing him carrying bullets in his beard. Many Western volunteers make their way to Syria through Turkey, often joining up with the Kataa'ib - the British Brigades - before taking part in hit-and-run operations deep within Syrian territory. Several jihadists from the UK are said to have been killed, one of them the son of a London antiques dealer. However, it is those who survive (and the fact that European-based jihadists can travel with ease to and from the war zone) that are concerning security officials, particularly as many of the returnees make no secret of their desire to bring religious war back to their home cities. "Britain will be next, Britain will be, inshallah (God willing), in the Islamic world," one Islamist blogger has boasted. Not surprisingly, Theresa May, the Home Secretary, has said she wants to introduce legislation that would give her the power to strip returning British jihadists of their citizenship, even if it means rendering them stateless. The civil rights lobby will no doubt have a field day preventing the introduction of such measures. But without them it is hard to see how we can prevent a new generation of al-Qaeda militants from bringing carnage to the streets of Britain.