A Russian diplomat in Tokyo on Monday criticized Japanese police over their investigation into alleged espionage activities involving a Russian military attache, saying the incident was plotted by forces in Japan that are unhappy with relations between the two countries.

Sergei Yasenev, first secretary at the Russian Embassy in charge of press affairs, called the allegation "an act of provocation."

However, he remained cautious over possible retaliatory measures against Japan, only saying that Russia would wait and see what course Japanese authorities take.