A spokesman for the Ukrainian military has said the country has not seen any significant increase in fighting in the eastern Donbass region in the last few days.

Earlier this week, Moscow accused Kiev of trying to provoke a conflict over Crimea. That has triggered worries in Ukraine that Russia may be planning to ramp up fighting in the war between Kiev and independence-seeking insurgents in eastern Ukraine.

On Friday, the Russian Defense Ministry said the country has deployed its advanced S-400 air defense missile system to the Crimean Peninsula. The announcement comes two days after President Vladimir Putin promised to take counter-measures after "clashes" between Russian forces and Ukrainian "saboteurs" in northern Crimea. Ukraine denied Putin's remarks.