A top Muslim leader has warned that ISIS is recruiting young Irish people to their cause.Irish Independent

Irish police arrested a man in Dublin earlier this week who they suspected of being an ISIS extremist and who had been under surveillance since he was deported from Turkey.

Last Thursday the suspect attempted to fly from Dublin to Istanbul, but he was sent back to Ireland as authorities in the Turkish city felt that there were “irregularities” with the Eastern European passport he was using.

On his return to Dublin, Irish police (gardaí) made the decision not to arrest him but placed the man in his 30s under surveillance as he left Dublin airport.

Earlier this week, however, gardaí decided to arrest the man and his Dublin home was raided on Monday. He was brought to a police station in the city center for questioning and his passport was seized.

Gardaí feared the man was involved with ISIS but could not confirm this.

Gardaí feared the man was involved with ISIS but could not confirm this.

Although the gardaí believe the man to be an ISIS sympathizer, they could not unearth any evidence to suggest that he was linked with terrorism, and following questioning by anti-terrorist officers from the Special Detective Unit, the suspect was released without charge.

Sources told the Irish Independent that they believe an “overt and covert surveillance” will continue to follow the suspect as a file is prepared for the DPP.

Garda Commissioner Noirin O’Sullivan has warned that terror attacks such as the shooting in Tunisia earlier this month in which three Irish people were killed can happen “anywhere, any time”.

Three Irish people were killed in a recent terrorist attack in Tunisia.

Three Irish people were killed in a recent terrorist attack in Tunisia.

"We must be aware of new terror threats," said O’Sullivan.

“From an Irish perspective, when we hear of victims of a barbaric terrorist attack on a beach in Tunisia with Irish names and addresses, and the outpouring of sympathies at the funeral, it just brings it into sharp focus that anybody can be a victim, any time, any place.

“Ireland has a history of having to deal with its ‘indigenous terrorist threat’ but we must also be aware of new challenges,” she continued.

“We’re very mindful that while we don’t have any significant intelligence of an attack here in Ireland, nevertheless we remain very, very mindful and have a shared interest with our partners right across the globe.”

The arrest comes as an anti-Islamic group in Co. Kerry is protesting the building of a new mosque in Tralee.

The Irish branch of PEGIDA (Patriotic Europeans Against the Islamization of the West) handed out anti-Islam flyers in Tralee town center earlier this month and told Radio Kerry, “Islam is taking over, all over the world. When they become the dominant religion [in an area] they impose their own laws on people."

Dr. Rizwan Khan, chairperson of the Kerry Muslim group, the Kerry Islamic Outreach Society, has since spoken out against the protest saying, “Those people [making negative comments] are not getting their knowledge of Islam from first hand experience and so makes them stereotype.

“Many people have approached us to talk about Islam, they ask us questions about ISIS, Boko Haram and many acts of terrorism and we give them a very straightforward answer; that those groups do not belong to Muslims at all.”