Top Merkel aide says Turkey's conduct 'unacceptable'

German Chancellor Angela Merkel and head of the chancellery Peter Altmeier before cabinet meeting at the chancellery in Berlin, Germany, March 15, 2017. REUTERS/Fabrizio Bensch

BERLIN (Reuters) - Turkey's behaviour is "unacceptable" and Germany has a duty to protect its citizens and companies but also wants to maintain strong ties with Ankara, German Chancellor Angela Merkel's chief of staff said on Sunday.

Relations between the NATO allies have deteriorated since Turkey arrested six rights activists, including one German, two weeks ago as part of a wider crackdown since last year's failed coup against President Tayyip Erdogan.