FRENCH authorities are making unprecedentedly broad use of discretionary powers under an anti-terror law to keep hundreds of people they deem to be potential security threats away from the biggest event modern France has ever organised.

Minorities, largely with backgrounds in former French colonies, are often among those forbidden from leaving their neighbourhoods and required to report daily to police, their lawyers say. Some are alarmed by the sweeping use of what one described as “a terribly dangerous tool.”

Some of those now restricted in their movements, with orders that don’t require prior approval from judges, include a man who had mental health issues in the past but is now receiving treatment.