South Wales police have issued a statement saying they are "increasingly concerned" with the numbers of young people travelling to Syria to fight, but the issue is "not unique" to Cardiff or Wales.
"Travelling abroad for the purpose of engaging in terrorist related activity is an offence and we will seek to prosecute anyone engaged in this type of activity," The statement said.
"The issue is not unique to Cardiff or Wales and is a priority for police and security services across the UK.
It is recognised that people want to offer aid and support to the Syrian people, the safest way to do so is to donate to a UK registered charities that have ongoing relief operations."
Leaders of a Cardiff mosque, attended by 3 young men who are now fighting in Syria, say they had nothing to do with their radicalisation.
The Home Secretary has told ITV News that young women have left Britain to fight for the extremists group ISIS in Syria and Iraq.