PARIS - France's prime minister on Friday announced steps including prison isolation zones and more stringent licensing rules for faith-based schools to combat what he called a slow-burning threat from Islamist radicalization.In a traditionally Catholic country that is home to Europe's largest Muslim community, President Emmanuel Macron has already imposed tougher legislation after attacks by Islamist militants killed more than 230 people in the past three years. But he is under pressure to address voter fears of broader radicalization at mosques manned by radical preachers and prisons that offer fertile ground for proselytizers of a hardline Islam at odds with France's secular foundations.Among the measures promised by Prime Minister Edouard Philippe were the creation of isolation zones for Islamist militants in France's prisons and more scrutiny on the licensing of faith-based schools that opt out of the state-funded system."We cannot ignore this slow-burn process," he told a news conference in Lille, northern France."Islamist radicalization is a threat to our society, and not just when it leads to violence. It's a challenge every time the law of the state is respected only if compatible with religious tenets."Philippe also promised better screening of people hired as coaches sports centers.The scale of the challenge was highlighted by a report for the Interior Ministry.The report by a senior civil servant warned that sectarian sentiment or behavior was rising in parts of France, notably in poor urban areas where Muslims more openly resented or challenged obligations of secular public life.He cited examples of young Muslim girls being kept away from school swimming, sculpture classes and choir activities frowned upon by some of the country's estimated 5 million Muslims.The report also highlighted fears about the number of young people being taken out of secular state-funded schools to teach them at home or put them in strictly faith-based schools.Philippe said some 74,000 pupils entered schools outside of state system last year, calling the trend worrying if small compared with 12 million in education. The report said the number concerned had doubled in five years.Such opt-out schools need licensing and that would be made tougher by law shortly, Philippe said.