BERLIN—Russia expelled a German diplomat in Moscow in retaliation for Berlin ordering the departure of a suspected Russian spy, a German official said Saturday, as tensions escalated between the two countries over the Ukraine crisis.

“An employee of the German Embassy in Moscow has departed as a result of a retaliatory measure imposed by Russian authorities,” a government official in Berlin said. “We are disappointed by this unjustified action and have expressed this to the Russian government.”

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