"Fear of terrorism in Berlin," read the front page of Berlin-based daily Der Tagesspiegel on Tuesday, a day after a seven-ton truck plowed into a Christmas market in the heart of the German capital, killing 12 and wounding dozens.

German police are investigating the event as a terrorist attack. Early this morning, police raided a hangar that serves as refugee center. The suspected attacker, who was apprehended 2 kilometers from the scene of the crime, is a 23-year-old Pakistani who arrived in Germany as an asylum seeker in February, German tabloid Bild reports. Chancellor Angela Merkel said it was "difficult to stomach" that the assault was the work of someone who had come to Germany seeking asylum and that it was "particularly disgusting" for volunteers helping refugees.