Ukraine has denied a Russian statement on troops attempting to invade Crimea and plotting terror attacks on the peninsula.
Ukrainian Defence Ministry has said that Russian Federal Security Service (FSB) statement does not correspond to reality.
It described the FSB's statement as an "attempt by Russia to justify the redeployment of its military units" in Crimea.
On Wednesday, the FSB said in a statement that over the weekend, it prevented several groups of armed "saboteurs", who were members of the Ukrainian Defence Ministry's intelligence forces, from invading Crimea.
An FSB officer and a Russian serviceman were killed in clashes with the "saboteurs", the statement added.
Armed groups were preparing terror attacks on the peninsula's infrastructure, which were aimed at destabilising the social and political situation in Crimea on the eve of federal and regional elections, read the statement.
Few days back, the Ukrainian State Border Service said that Russia was building up troops levels along the contact line separating Crimea and Ukraine's Kherson region.
Russia has not made official comments on the claim.
Russia in March 2014 absorbed autonomous republic of Crimea and the city of Sevastopol following a referendum, which was recognised by Moscow but rejected by Kiev.
Around 9,000 people were reported to have been killed in the conflict in eastern Ukraine that followed the Russian annexation of Crimea.
The European Union and US imposed sanctions on Moscow in response to its seizure of the territory.