LONDON (AFP) - Anyone travelling from the UK to Syria faces arrest on their return, a senior police chief warned on Saturday, fearing they pose a terror threat to Britain.
Manchester's police chief Peter Fahy, who leads the Association of Chief Police Officers' "Prevent" counter-terror strategy, said there was a "huge concern" about people travelling to Syria to fight in its civil war.
Sixteen people have been arrested on suspicion of terror offences this month after returning from Syria, compared with 24 in the whole of last year, the BBC reported.
Syria "is an incredibly dangerous place and you will be arrested and stopped at the border if you try and come back", Mr Fahy told BBC radio.
"We've stopped quite a number of people because we're very, very clear about what will happen."
A defector from the hardline Islamic State of Iraq and al-Sham warned this week that al-Qaeda was training hundreds of British people fighting in Syria to become jihadists and urging them to carry out attacks when they return home.
The defector, known as Murad, told The Daily Telegraph newspaper that other recruits from Europe and the United States were also being trained to make car bombs before being sent home to form terror cells.
Mr Fahy said there was "a real worry about those who may be radicalised, who may have been engaged in terrorist training.
"If people are engaging in terrorism or planning terrorism or fundraising for terrorism then that is clearly against the law," he added.
Mr Fahy said the police were concerned about the welfare of young people who have travelled to Syria and said they could be put on special programmes.
He said police would work with youth organisations and schools "essentially to make sure these people haven't been affected and try and make sure they're not a threat to this country".
The "Prevent" strategy provides practical help to stop people from being drawn towards terror and provides advice and support.
Britain's intelligence services estimate that around 500 British fighters are currently in Syria.
The Times newspaper said on Saturday that security screening at airports has been increased, with the focus on people flying in from Istanbul, a staging point on the route into Syria across the Turkish border.
Two British women were on Wednesday charged with raising money suspected of funding terrorism in Syria, Scotland Yard police headquarters announced.
Two British men were charged last week with travelling to Syria for terror purposes, while another man was arrested on suspicion of attending a terror camp in the war-ravaged country.