Germany said on Friday it would seize the personal identity cards of German radical Islamists it suspects of planning to travel to Syria or Iraq to join Islamic State forces there.
Germany, like many other European countries, is struggling to prevent a wave of would-be fighters, some of them just teenagers, from joining Islamic State, the militant group that has seized swathes of Syrian and Iraqi territory.
Authorities fear they will return battle-hardened and full of hate for the West and could plot attacks on home soil.
German intelligence estimates that at least 450 people have left Germany for Syria and that around 150 have returned. Many are the subject of criminal investigations.
Under existing legislation, Germany can seize passports to keep citizens at home, but not the personal identity cards which every German is obliged to carry at all times.
The identity cards alone are enough for Germans to gain entry to other European countries and also, crucially, to Turkey, from where would-be fighters can slip across the long border into Syria.
Interior Minister Thomas de Maiziere said on Friday he had agreed with Germany's 16 federal states to draw up new powers to confiscate identity cards and to issue a replacement document, which would not suffice for travel.
The states also agreed to boost information-sharing on radical Islamists in Germany.