There is no sign that Islamist militants posing as refugees have entered Germany to commit an attack, the head of the German police said, responding to concerns following the attacks in Paris that an open-door refugee policy poses a security risk.

Islamic State has claimed responsibility for last Friday's coordinated suicide bombings and shootings in Paris which killed at least 129 people.French prosecutors have identified one of the seven dead assailants in Paris as a foreigner fingerprinted in Greece last month along with hundreds of thousands of refugees fleeing Syria's civil war. His role in the carnage has fueled fears that Islamic State has taken advantage of the refugee crisis to slip militants into Europe.

Germany expects to take in about one million refugees this year, far more than any other European country, but Holger Muench, president of the BKA federal police, played down fears that the influx made the country more vulnerable to attack." There is a threat level that should be taken seriously, but we have no concrete indications of planning for an attack," he told Tuesday's edition of Die Welt in an interview." So far, we have no indication that a terrorist has entered Germany as an asylum seeker in order to perpetrate an attack."

However, Muench added that about 10 individual migrants were under investigation as possible jihadists or war criminals, following tip-offs mostly from other refugees.The head of Germany's BfV domestic intelligence services warned at the weekend that militants might exploit the chaotic conditions sometimes created by Europe's migrant crisis.More than 750 suspected Islamists have traveled to the Middle East from Germany and the authorities know of about 70 who have returned from military training camps, Muench said.

Since the Paris attacks, some lawmakers in Chancellor Angela Merkel's conservative bloc, especially those in Bavaria which is bearing the brunt of the refugee influx, have stepped up calls to limit the number of people allowed in.Merkel's mantra "we can manage" rings hollow to some voters and has cost her support in the last couple of months. However, she has not softened her stance since the Paris attacks.