The head of Germany's domestic intelligence agency said Friday that Islamic State fighters disguised as refugees have crossed into Europe undetected.
Hans-Georg Maassen made the comments after German authorities were able to thwart a potential Islamic State attack in Berlin recently.
"Then we have repeatedly seen that terrorists ... have slipped in camouflaged or disguised as refugees. This is a fact that the security agencies are facing," Maassen said in an interview. "We are trying to recognize and identify whether there are still more IS fighters or terrorists from IS that have slipped in."
Officials report receiving more than100 tips from citizens that indicated the presence of Islamic State fighters among the refugees currently being sheltered in Germany. Still, Maassen cautioned against panic.
"We are in a serious situation and there is a high risk that there could be an attack. But the security agencies, the intelligence services and the police authorities are very alert and our goal is to minimize the risk as best we can," he said.