An ISIS general once pictured decapitating a prisoner is back in Europe with up to 400 of his most trusted soldiers after fleeing the war zone in Syria, it has been claimed.

Ex-NATO soldier Lavdrim Muhaxheri and his men are among thousands who have fled after ISIS suffered devastating losses in war-torn Syria, according to sources in the Italian intelligence services.

Many of the fighters are feared to have disguised themselves as refugees in order to cross borders to get into Europe without being identified, according to information leaked from the spying agency.

ISIS general Lavdrim Muhaxheri, who was once pictured decapitating a prisoner, is back in Europe with up to 400 of his most trusted soldiers after fleeing the warzone in Syria, it has been claimed

Muhaxheri, also known as Abu Abdullah al Kosova, is not only a Kosovo Albanian ISIS leader but also one of the most public figures because of his foreign roots and his efforts to recruit other foreign jihadi fighters.

He left for Syria in late 2012 and has appeared in several propaganda videos, calling Albanians to join jihad, and has uploaded photographs of himself appearing to decapitate a man, as well as a video where he kills a captive with a rocket.

On September 24, 2014, the US State Department designated Muhaxheri as a global terrorist.

Italian newspaper 'L'Espresso', quoting the intelligence services, said that between 300 and 400 members of the Islamic 'caliphate' had come to Kosovo with him.

His arrival coincided with plans for an attack on Israel's national soccer team and other targets which he is believed to have masterminded after arriving back in the country.

Prosecutors say Muhaxheri and fellow ISIS fighter Ridvan Haqifi planned attacks on international and state institutions, ultimately with the intent to establish an Islamic state.

They say he planned to attack the Israeli football team during a match in Albania and Kosovo government institutions, as well as Serbian Orthodox Church sites, were also potential targets.

Ex-NATO soldier Lavdrim Muhaxheri and his men are among thousands who have fled after ISIS suffered devastating losses in war-torn Syria, according to Italian intelligence services

In total 19 people were arrested as a result of the plot being uncovered, with the trail to the mastermind reportedly leading back to Muhaxheri.

Quoting an unnamed security source the paper said: 'Numerous jihadists are returning to Europe and the Balkans, aiming to hit the old continent at its heart. Some of them are being identified by security services, but many others manage to cross the borders without being identified.'

The Italian intelligence reports however have so far been rejected by Kosovo police, who despite admitting that he was probably behind the attacks, insisted that their information was that he was still in Syria.