INTERPOL secretary-general Jürgen Stock has sounded the alarm on a potential new wave of radical Islamic terrorism, saying that Islamists about to be released from prison could pose a new terror threat to Europe.

Mr Stock said that the threat comes from both jihadists coming home from fighting in the Middle East and from supporters who had been jailed for supporting the Islamic State but were given short prison sentences, Die Welt reports.

“We could soon be facing a second wave of other ISIS-linked or radicalised individuals that you might call ISIS 2.0,” Stock said, adding: “A lot of these are suspected terrorists or those who are linked to terrorist groups as supporters who are facing maybe two to five years in jail.

“Because they were not convicted of a concrete terrorist attack but only support for terrorist activities, their sentences are perhaps not so heavy,” he noted.

“[T]his generation of early supporters will be released in the next couple of years, and they may again be part of a terrorist group or those supporting terrorist activities.”

The warning follows that of France’s Minister of Justice Nicole Belloubet, who said earlier this year that around 450 radical Islamic extremists were set for release from French prisons by the end of next year, with 50 of them considered a terrorist risk.

Ms Belloubet claimed that the French state would be monitoring the activities of the prisoners upon release and many if not all are likely on the terror watch list, known as the S-File, along with thousands of others.

However, many of the perpetrators of past terror attacks in France, including the recent terror attack in Strasbourg, were also S-File members — and despite being on the list, the government was unable to thwart their attacks.

A lack of manpower could be a major obstacle to authorities keeping track of radicals according to Yves Trotignon, a former agent of the General Directorate for External Security (DGSE), who said intelligence officials simply do not have the resources to keep track of all 25,000 or so S-file members.

Follow Chris Tomlinson on Twitter at @TomlinsonCJ or email at ctomlinson(at)breitbart.com