Various types of directional antennas are pictured on the roof of a skyscraper in Berlin, November 5, 2013. Germany's Foreign Ministry said on Tuesday it had asked the British ambassador to come and discuss a report that Britain was operating a covert spying station in Berlin, using hi-tech equipment housed on the embassy roof. Documents leaked by former U.S. National Security Agency contractor Edward Snowden show that Britain's surveillance agency is operating a network of "electronic spy posts" from within a stone's throw of the Bundestag and German chancellor's office, British newspaper Independent reported. REUTERS/Fabrizio Bensch (GERMANY - Tags: BUSINESS TELECOMS)