The German government has announced a series of counter-terrorism measures in the wake of attacks last month claimed by the so-called Islamic State.
Under the measures, Germans with dual nationality could be stripped of their citizenship if they join foreign terror organisations.
Around 820 people have left Germany to fight alongside jihadist groups in Syria and Iraq, according to estimates by Germany's secret service.
With around one in three fighters having since returned to Germany, fears are running high of the threat they may pose on European soil.
A new law would also make it easier for the authorities to detain a person on the grounds of public safety.
IS claimed two attacks in Germany in July; an attack on a train, which left a number of passengers hurt and a suicide bombing in the city of Ansbach which injured 15 people.
The attacks coincided with a gun assault by a mentally unstable teenager on a shopping centre in Munich which left nine people dead.
While that attack was not linked to Islamist terrorism, it has heightened the sense of vulnerability.
German Interior Minister Thomas de Maziere has promised an extra 4,500 police officers, and a €2 billion increase in security related spending by 2020.
The measures announced today will be seen by some as political manoeuvring by Chancellor Merkel's CDU party ahead of next year's general election.
The chancellor's approval ratings fell 12 points to 47% at the beginning of August and her party is desperate to limit the influence of the right wing AfD party, which has campaigned relentlessly on the refugee issue.
The move may also be intended to put some distance between the CDU and their centre left coalition partners, the SPD, who have opposed any ban on dual citizenship.
