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Dutch Professor Ruud Koopmans warned the EU today to block the entry of any refugees whose identity cannot be categorically confirmed. Prof Koopmans, who is the Director of the Research Unit Migration, Integration, Transnationalisation at the Berlin Social Sciences Centre, said that of the 1 billion adult Muslims in the world, “half of them are attached to an arch-conservative Islam which places little worth on the rights of women, homosexuals, and people of other faiths".

GETTY Professor Ruud Koopmans claimed there are over 50 million Muslims willing to sanction violence

In an interview with a German news website he claimed that of these 500 million conservative Muslims, at least – and probably more – than 50 million are willing to sanction violence. The migration researcher stressed that not every one of them was ready to exert violence directly. But he added: "They support the radicals, they encourage them and provide them shelter or simply keep their mouths shut when they observe radicalisation".

GETTY The migration researcher stressed that not every one of them was ready to exert violence directly

He said he considers his own estimate of 50 million “an understatement", citing studies that show eight percent of German Muslims agreed to the use of violence against “infidels”.

They support the radicals, they encourage them and provide them shelter Dutch Professor Ruud Koopmans

In his own country 11 per cent of Muslims agreed with the statement: “There are situations in which it is acceptable for me from the perspective of my religion, that I use violence". In several Islamic countries, 14 per cent of local Muslims think suicide attacks against innocents are “sometimes” or “often” justified to defend Islam, said Koopmans, citing a study by the US based Pew Research Centre.

GETTY He said the EU should be more careful to let suspected Islamists have uncontrolled within Europe

"I'm very conservative with my estimate of 50 million violent Muslims," added Prof Koopmans. The expert sees a “clear difference” between anti-Islam baiting and justified criticism of Islam. He went on: "There is nothing wrong with foreign cultures, as long as they are looking for the connection to the majority in society and actually enrich our countries.