Cardiff has an ongoing problem with the radicalisation of young Muslims, said an academic who has studied the issue, BBC reported.
Dr Suraj Lakhani, of Cardiff University, who recently completed his doctorate – A Social Analysis of Radicalisation in the UK, told BBC Radio Wales: “As far as I’m aware, there has been an issue in Cardiff for a while now.
“This is a concern that has been raised not only by the intelligence services and the Welsh government, but also South Wales Police and local Muslim communities.
“People have been saying that something needs to be done in Cardiff, they need support.
“There has been a threat for a while as there has been in other parts of the country as well. Yes, there has been a threat and it’s still ongoing.”
He said he believed the internet played a “big role” in radicalisation but there was also “face to face interaction”, although not from the mosques.
That was echoed by Saleem Kidwai, secretary general of the Muslim Council of Wales, who insisted there was no problem in south Wales mosques.
He believes the men may have travelled to Syria for humanitarian reasons and were radicalised there.
He said Islamic leaders and scholars could provide an important role in the fight against radicalisation.
“People who are radicalising these youngsters probably are misquoting the verses from the Koran and the hadiths of the prophet for their own political ends, rather than what the true picture is,” he said.
“It is only the scholars of Islam – they can give the true interpretation of it, which I know is very different than what the extremist ideologists are portraying.”
Sheikh Zane Abdo from the South Wales Islamic Centre in Cardiff, where Nasser Muthana and his brother have prayed in the past but not for years, has also said he believes there is a problem with extremism in Cardiff. He said he believed “a certain amount of radicalisation” could occur online.
“It very simple, very easy for a person just to click on (it) and become radicalised over a long period of time,” he told BBC News.
“The fact that the video they’ve shown… I guarantee many young people who are susceptible to this kind of message will have watched the video and maybe (be) encouraged to follow in the footsteps of Nasser and his brother.
“A platform has been given to this video which really shouldn’t have been given.
“So there’s issues around the internet and issues around people who can radicalise, can talk to young people.”
He said the pair had been normal teenagers before they went through a “very strange period” when they started expressing “certain views”.