Russia is vowing a response to the death of a civilian from a shell it says was fired by Ukrainian forces.  Moscow and Berlin are calling for the resumption of talk on the Ukraine crisis as soon as possible.

Russian investigators say a man was killed and a woman injured when a shell fired from Ukrainian territory landed in the courtyard of a private house in the village of Donetsk.  That’s on the Russian side of the border, 200 kilometers from the Ukrainian city of the same name where pro-Russian separatists are holding out from the advancing Ukrainian troops.

“Naturally, this action will not be left without a corresponding reaction,” said Russian deputy Foreign Minister Grigory Karasin.  “The talk with the Ukrainian side on this issue is going to be serious and tough.”

It follows an escalation in violence in Ukraine east.  Government troops carried out air strikes on separatist positions, after the pro-Russian insurgents fired Grad missiles at Ukrainian troops, killing 23 of them.  The Ukrainian army also retook a number of towns that had been controlled by separatists in the past fortnight.