Vadim Savitsky/Russian Defense Ministry Press Service via AP Russian S-400 long-range air 
- Just days after a major clash between Russia and Ukraine, the Russian military has announced that it will be sending more S-400 surface-to-air missile systems into Crimea.
- Tensions between Russia and Ukraine have soared to levels not seen since Russia's annexation of Crimea in 2014 following an incident Sunday in which Russian ships rammed a Ukrainian tugboat and fired on two Ukrainian gunboats in the Sea of Azov.
- Ukraine called the latest incident evidence of Russian aggression, with the Ukrainian president warning that the country faces a threat of "full-scale war" from Russia.
The Russian military announced Wednesday that it will be deploying advanced anti-aircraft missiles to the Crimean peninsula as tensions between Moscow and Kiev rise.
A division of S-400 Triumph surface-to-air missiles will be sent to Crimea for "combat duty," the state-backed TASS news agency reported Wednesday, citing information provided by the Southern Military District's press service. "In the near future, the new system will enter combat duty to defend Russia's airspace, replacing the previous air defense system," a spokesperson told the official news agency.
Sputnik News, another Russian media outlet owned by the Russian government, indicated that this is the fourth S-400 air defense battalion the country that has deployed to Crimea. The S-400 surface-to-air missile system is one of the most advanced air defense systems in the world today, with the ability to target aircraft, missiles, and even ground targets.
A column of what appeared to be anti-ship missile systems was spotted on a highway headed toward the Crimean city of Kerch Tuesday, the government-funded RT television network reported.
News of missile deployments to Crimea come just a couple of days after a serious naval clash between Russia and the Ukraine on Sunday in the Sea of Azov, which a 2003 treaty signed by both countries clearly states is shared territorial waters.
During Sunday's confrontation, Russian vessels rammed a Ukrainian tugboat and opened fire on two other ships before seizing the boats and taking their crew into custody.
Russia asserts that the ships, which were traveling to the Ukrainian port city of Mariupol from Odessa by way of the Kerch Strait, failed to request authorization and engaged in dangerous maneuvers. Moscow has yet to provide evidence to support these claims.
Ukraine argues that the incident was evidence of Russian aggression and released a video from aboard one of the Russian ships that was intercepted by Ukrainian authorities. In the video, the Russian sailors can be heard shouting "crush him" as the Russian vessel rams the Ukrainian tugboat.
Two dozen Ukrainian sailors are being held in detention. Half of that group will be held for at least two months, with the whole facing up to six years in prison, according to news reports.
NATO has condemned Russia's actions. The US mission to the United Nations stated that this is "an arrogant act that the international community ... will never accept."
"I don't want anyone to think this is fun and games. Ukraine is under threat of full-scale war with Russia," Ukrainian President Petro Poroshenko said Tuesday, adding that the number of Russian units stationed along the border has "grown dramatically."
Ukraine has declared martial law, which is already beginning to go into effect across the country.