Russia has deployed a regiment of its advanced S-400 air defense missile system to Crimea as a dispute deepens between Moscow and Kiev over the security situation in the Black Sea peninsula.
Russian news agencies made the announcement on Friday, citing a statement from Russia’s Defense Ministry.
The ministry had earlier in the day announced that its navy would start to hold three-day military exercises in the Black Sea to practice repelling underwater attacks by saboteurs.
Russia's Black Sea Fleet based in Crimea is taking part in the military exercises. More than 10 warships, MI-8 and Ka-27PS helicopters are participating in the training.
“During the drill we are going to practice the issues of both operational and technical support. These include operations to counter underwater sabotage, navigational and hydrographic exercise, search and rescue missions,” said Russian Navy Commander Admiral Viktor Chirkov.
'Ties with Ukraine could be severed'
Meanwhile, Russian Prime Minister Dmitry Medvedev said on Friday that Moscow could break diplomatic relations with Kiev over the security incidents in Crimea.
Russian state news agencies quoted the prime minister as saying that he is not interested in severing the ties, but "if there is no other way to change the situation, the president could take this step."
The Russian Federal Security Service said on Wednesday that it had thwarted an incursion by the Ukrainian military into Crimea over the weekend, saying two Russians were killed in the incident.
Ukraine’s defense intelligence rejected Russia’s claim over the incursion, saying it was based on “fake information.”
The Friday statement from by Russia’s Defense Ministry came two days after President Vladimir Putin ordered measures to ramp up security in Crimea.
The Kremlin said in a statement on Thursday that the Russian president held a meeting with his security chiefs to review “additional measures for ensuring security for citizens and essential infrastructure in Crimea.”
“Scenarios were carefully considered for anti-terrorist security measures at the land border, in the waters and in the airspace of Crimea,” the statement read.
The UN Security Council also held a closed-door meeting on Thursday at Ukraine's request to discuss the growing tensions.
The developments have ratcheted up tensions and prompted fears of a possible wider conflict.
People in Ukraine’s Black Sea peninsula of Crimea voted for rejoining the Russian Federation in a referendum in March 2014. The move angered the West which branded it as Moscow’s annexation of the territory.