German politicians voiced their outrage on Friday after a report detailed an alleged Russian plot to assassinate the head of German arms maker Rheinmetall, as a Kremlin spokesman denied any involvement from Moscow. According to the report, which was published by US broadcaster CNN on Thursday, US intelligence earlier this year uncovered Russian government plans to assassinate Armin Papperger, the chief executive of Rheinmetall. Citing “five US and western officials familiar with the episode,” CNN said German authorities were notified of the plot and subsequently increased security for Papperge…