More than 60 people suspected to have joined up with the militant group Isis (now known as Islamic State) have been arrested after returning to the UK in 2014, according to the defence secretary.
Michael Fallon said many of the suspects could be brought before the courts over allegations they travelled to Syria to fight alongside the terrorist organisation, also known as Isil.
He told BBC Radio 4's The World This Weekend: "Over 60 returning fighters have now been arrested and some of those will be brought before the courts.
"Isil is a proscribed organisation so these people are guilty of a criminal offence. And if we can get them into the courts on their return that's what we will do. We have to put evidence before the court and that's what is going on now."
Metropolitan Police confirmed there have been a total of 69 Syria-related arrests in the first half of 2014 for alleged offences including terrorist financing, preparation of acts to commit terrorism and attending a terrorist training camp.
A spokesperson added: "A national campaign was launched on April 24, at the beginning of the second quarter, warning about the dangers of travelling to Syria but it is too early to say categorically whether this has affected the number of arrests.
"Police have recorded 25 Syria related arrests for the whole of 2013 compared to 69 arrests for the first half of 2014 demonstrating a significant rise."
MPs voted in favour of launching airstrikes in Iraq as part of the military action against Isis.
David Cameron said military action was the only way to deal with the "psychopathic terrorists that are trying to kill us" and did not rule out further strikes in Syria.