“It was either fight with ISIS or they will kill me,” Abu Omer, who claims he was captured and forced to fight for the terror group.
"All of the countries of the world have fighters inside Syria fighting with ISIS," he says. "The most European fighters were from France, there were some from the UK, and there were Irish, but the most was French.
“There was Chechen, Libyan, Moroccan, Tunisian, Egyptian, and Saudi Arabian, some also from America.
"ISIS depends on Chechens the most," for their military expertise and violent nature, "If ISIS wants to take over any area, they send the Chechens in.
"The Irish fighters are perfect snipers; they use them sometimes with the Chechens, in any place they need snipers, they move the Irish," he told the Irish Independent.
"They are part of the Al Khalifa army (Caliphate army), and fought in Kobane," before the Kurdish Peshmerga forces with the help of coalition forces, defeated them.
He claims there are around 40 Irish fighters in Deir ez Zor, while Ireland’s Department of Justice says that 30 Irish fighters have left to fight in Syria and Iraq. Sources in the US State Department say this number is actually closer to 70 in total.
Of the Irish he came across, one was known as 'Abu Omer al-Irlandi', another, 'Abu Yazid al-Irlandi'. They work alongside British jihadists, "you see them together,” he says.
Abu Omer (not his real name) is a captured Syrian fighter and says he followed orders and assumed a role in the frontline for ISIS is the city of Deir Ez-Zor from July until December 2014. He says he escaped and is now in hiding in the city of Urfa, in the Turkish border with Syria.
"It's difficult for anyone to leave," explained Abu Omer. "People have no money and they have families" to take with them. There are also several checkpoints.
He said that foreign fighters for ISIS believe they “are, the Islamic State” and not fighters in a foreign land. Instead, they believe they are the creators of the new Islamic caliphate.
He adds that foreign fighters from Europe have the most virulent ideology.
"Sometimes the Saudi or other Arabic fighters might forgive you if you are caught smoking or caught breaking the rules," but not the Europeans.
He said Europeans “cut the heads.”
"Another example: in a village in the Deir ez-Zor countryside, the Europeans killed around 3,000 people in the village, using French fighters," he says.
When ISIS decide someone is 'kuffar' – a non-believer, or someone that has rejected Islam – "they use European fighters to cut heads, to kill people".
When asked if he knew of any Irish female jihadists he said: "I've known of British women who have joined Daash, but never heard of any Irish women.”
He spoke about the restrictions on women:
"I didn't see any women killed by Daash (the local Arabic name for Isis). Girls are forced to get married to European and other fighters. Women aren't allowed learn or go to school; they have to stay inside the house. She can't go outside without her father, brother or husband, nor gather together with other women unless very necessary.”
He said high profile deaths of journalists and aid workers appear to be carried out by one of ISIS’s most barbaric operatives, “Jihadi John,” who is said to have been a rap singer from London in his previous life.
"That's what I heard about him. His security is very high – like Abu Omar al-Baghdadi" - ISIS' founder from Baghdad, Iraq.
"They move him place to place; they're afraid he will be tracked by satellite".
"They use him because he's a British man to kill the Europeans and westerners.”
Regarding reports that ISIS is enticing radical men and women from countries around the globe to leave their home and fight for the terror group, he said: "They can attack Europe any time they want; they have members inside Europe, inside America, inside Britain, they're just awaiting a decision from al-Baghdadi.
"They focus on America, Britain, France and Denmark, because of the cartoons about Mohammad,” he warned.