CNN has a detailed report on the travels of four ISIS operatives who made their way from Raqqa, Syria to Austria posing as refugees last year. Two of the four would later make their way to France and blow themselves up at the national stadium in Paris. However, two more operatives who were apparently supposed to be part of the Paris attack were delayed after their fake passports were discovered in Greece. CNN reports:

Haddadi and Usman, who was identified by investigators as a suspected bombmaker for the Pakistani terror group Lashkar-e-Taiba, set out from the capital of the self-declared ISIS caliphate in Raqqa, Syria, six weeks before the Paris attacks.

They were part of a team, investigators concluded. The two others, Ahmad al-Mohammad and Mohamad al-Mahmod, would later blow themselves up outside the national stadium in Paris. The team crossed the border from Syria into Turkey in early October and headed for the Turkish coast…

The documents reveal fresh details about their journey and the way they posed as Syrian refugees, blending in with thousands fleeing the war-torn country.

They made the treacherous crossing from Izmir, Turkey, into Greece in a boat filled with dozens of refugees. But they were then intercepted by the Greek Navy.

The two who would go on to strike the Paris stadium passed through Greece and started moving across Europe toward their target in France. Greek officials declined to explain how the two got through.

But Greek authorities discovered Haddadi and Usman’s fake Syrian passports. The pair were arrested, their money was taken, and they were held for nearly a month.

Haddadi and Usman were released in October and continued making their way into the heart of Europe. They crossed the border into Austria and settled at a refugee center where they waited several weeks for the arrival of a third man, Abid Tabaouni. There was a raid on the refugee center and Haddadi and Usman were arrested but Tabouni escaped. In July, after months on the run, Tabouni was arrested in Brussels.

Investigators believe the three men, had they not been caught at the refugee center, would have carried out an additional attack in France.

The full report from CNN is lengthy but worth a watch if you’re interested in how ISIS operates its terror cells in Europe: