A police spokesperson from the German state of Lower Saxony, which was participating in the effort, confirmed that two arrests had been made but not the identities of those arrested.

Around 130 officers were on the ground in their search for suspects Ernst-Volker Staub and Burkhard Garweg, said Berlin police, who declined to give further details.

The search follows the arrest last week of a suspected RAF militant who had been on the run for three decades.

(Reporting by Oliver Denzer and Tom Sims; Editing by Alison Williams and Jan Harvey)