Dutch counterterrorism coordinator Dick Schoof has told the Associated Press that the "Islamic State" (IS) extremist group has between 60 and 80 operatives in Europe to carry out attacks there.

Dick Schoof also said in the interview on Friday that would-be fighters who might have otherwise traveled to the Middle East to support the jihadists there were being told by IS to stay put and prepare attacks in Europe. He said the fact that the number of "foreign terrorist fighters" remained constant did not mean that there was less of a potential threat from those who had remained instead of traveling.

Schoof also pointed out that IS fighters and supporters driven out of Syria and Iraq by government and international military operations were likely to come to Europe in the guise of refugees.

Returning fighters a threat?

The Dutch expert gave the interview while in New York to speak at a roundtable on "returning foreign terrorist fighters."

He said there were probably between 4,000 and 5,000 European "foreign terrorist fighters" currently in Iraq and Syria.

European authorities have expressed concern that such fighters could potentially pose a continued security threat if and when they return to their homes in Europe.

Schoof said the program in the Netherlands for dealing with such returnees combined "repression and prevention." On the one hand, fighters returning from Syria or Iraq were being taken into custody and prosecuted, and subjected to having their passports removed and assets frozen, he said.

Schoof: "The chance of attack in the Netherlands is real"

On the other hand, local authorities were providing education and psychological help if needed.

He stressed that the Netherlands did not tolerate "anti-democratic behavior," saying that "hate preachers" were being refused visas to enter the country.

Schoof has been National Coordinator for Counterterrorism and Security in the Netherlands since March, 2013. The NCTV unit is part of the Ministry of Security and Justice and is responsible for crisis management, counterterrorism and cyber-security.