THE ARREST at Heathrow airport last night of a man and woman off a flight from Egypt has underscored fears that militant Islamists are going to fight in Syria, only to return to put their training there into practice in the UK.

The police say the pair, both aged 26, are now being questioned at a central London station – where most terrorist suspects are interrogated initially. The two were arrested on suspicion of “the commission, preparation or instigation of acts of terrorism”. Two homes in east London are being searched.

Fears have been growing that new groups, or small cells, of ‘salafist’ or ‘jihadi’ extremists have been moving from the UK to Syria and joining in the fight there, along with affiliates from the Gulf region and local Syrian insurgents.