BERLIN German magazine Focus said on Tuesday that police special forces were storming a hangar at Berlin's defunct Tempelhof airport, which now houses a refugee accommodation centre.
On Monday evening a truck ploughed into a crowd at a Berlin Christmas market, killing 12 people and injuring 48 others. Police say they suspect it was a terrorist attack.
German media cited local security sources as saying that there was evidence suggesting the arrested suspect was from Afghanistan or Pakistan and had entered Germany as a refugee.
Neither police nor prosecutors were immediately available for comment.
(Reporting by Michelle Martin and Joseph Nasr; Editing by Emma Thomasson)