Joshua Molloy (24), from Ballylinan, County Laois was arrested along with two Britons having entered Iraq from Syria. The men were attempting to return home having been fighting alongside the Kurds in Syrian against the Islamic State group.

The three men were detained in the Iraqi city of Erbil, on Friday, the Sunday Times (subscription needed) reports. The Irish Department of Foreign Affairs has said it stands ready to provide consular assistance to Molloy. The British Foreign Office is also working on the two British citizen’s cases (Joe Akerman and Jac Holmes).

Molloy travelled to the Middle East in April 2015 to fight against the Islamic State terrorists, alongside the Kurds. They had been fighting with a Syriac Christian group, the MFS, which is allied to the Kurdish YPG in the fight against ISIS.

In the past 18 months hundreds of Westerners have joined Kurdish, Assyrian and other military units in the fight against ISIS.

The 24-year-old went to school at Ardscoil na Tríonóide, in Athy, County Kildare. He joined the British Army after school and served for four years. He left due to a lack of military action, the Irish Independent reports.

Before leaving for the Middle East Molloy told his family he was traveling to Turkey to with the humanitarian aid services.

Molloy had been interviewed a year ago, when he arrived in Syria for the first time. He said he was motivated to fight due to the his disgust at the Islamic State and their attempts to establish a global theocracy.

The Laois man and the two Britons were arrested on Friday by the Kurdistan Regional Government (KRG) as they were trying to return home. They were entering Iraq illegally from Syria. The KRG has closed the Iraq-Syria border.

The Sunday Times reports that they group had been promised help from the KFG but when this did not materialize they had made their own way across the border.

A spokesman for the British Foreign Office said they are working on the ground in Iraq to secure the release of the men.

A spokesman for Ireland’s Minister for Foreign Affairs, Charlie Flanagan, and the Department said “We are aware of the case and we stand ready to provide consular assistance. Minister Flanagan is being kept fully informed.”

Mark Campbell, a British-based activist for Kurdish rights, said Molloy parents are very worried.

He said "Joshua's parents would like to appeal to the KRG to release him and his friends."

Campbell last spoke to the men last Wednesday when they arrived in Sinjar, on the Syrian border.

Hannah Lucinda-Smith is a Turkish correspondent with The Times in Britain who interviewed Molloy when he arrived in Syria in 2015. Speaking to Newstalk she outlined how Molloy came to be arrested.

"The northern Iraqi has been tightening up its policy on those foreigners going to join the Kurds in Syria.”

She continued "They were unable to cross the border legally into northern Iraq - they were waiting for some weeks at the border trying to cross it illegally".

"When they finally did they were arrested by Iraqi security services; so they're now in a prison in Erbil, which is the capital of northern Iraq.”