BERLIN - German authorities have arrested a suspected high-ranking Islamic State militant in the western town of Mutterstadt, according to a Bild newspaper report on Tuesday. The newspaper quoted a spokesman from the Rhineland-Palatinate interior ministry confirming the arrest. He is suspected of being a 'high-ranking representative of the militant terror group IS,' the newspaper said. The newspaper, in its online edition, said that the man had been arrested during a routine police stop. It said German authorities had received a tip-off about the man from a prison in the neighbouring state of North Rhine-Westphalia.