(Reuters) Thousands of inmates about to be freed from European prisons at the end of their terms may have been radicalized as Islamist militants in detention and pose a risk, the European Union security chief said on Wednesday.
Returning fighters from Syria are also a concern, EU security commissioner Julian King told a news conference.
Over the last two decades Europe has been the target of several Islamist militant assaults, with a rise in deadly attacks from 2015, when more than 130 people were killed in Paris in a coordinated operation in mid-November.
Security forces in EU countries have since arrested hundreds of militants, with about 1,100 still being held on terrorism charges, King said.
