By Oliver Ellrodt and Caroline Copley
German forces have arrested two men suspected of links to Islamic State militants preparing an attack on Berlin, police and prosecutors say.
Police and special forces on Thursday (local time) raided four flats and two offices in the German capital and properties in the northern regions of North Rhine-Westphalia and Lower Saxony.
"Specifically [the raids] concern possible plans for an attack in Germany, even more specifically in Berlin," Martin Steltner, a spokesman for Berlin prosecutors, told Reuters TV.
The man detained in North-Rhine Westphalia was arrested in a shelter for refugees and arrived a short while ago in Germany claiming to be from Syria, Steltner said.
He is wanted by Algerian authorities, who believe he is a member of Islamic State, said Steltner. He is suspected of having had military training in Syria.
His wife was also arrested.
According to Berlin police spokesman Stefan Redlich, authorities are investigating another three Algerian men, of whom one was detained in Berlin.
German media reported that central Berlin landmarks and tourist attractions Checkpoint Charlie and Alexanderplatz were targets.
The Tagesspiegel newspaper, citing security sources, said leading members of Islamic State, who were responsible for the Paris attacks that killed 130 people in November, had given the order for an attack in Germany.
Prosecutors declined to comment on the report.