Ukraine's interim leader has called on Russia to cease all military aggression. The warning followed signs of an increased Russian military presence in the Crimean peninsula during the day.
Ukraine's interim president, Oleksandr Turchynov, called on Russian President Vladimir Putin on Friday evening to stop "provocations" in Crimea.
"Russia has sent forces into Crimea…they are working on scenarios which are fully analagous with Abkhazia, when having initiated a military conflict, they started to annex the territory," Turchynov said, referring to a disputed territory on Black Sea's eastern coastline.
"I personally appeal to President Putin to immediately stop military provocation and to withdraw from the Autonomous Republic of Crimea…it's a naked aggression against Ukraine."
Turchynov likened the open aggression to Moscow's strategy leading up to its war with Georgia in 2008.
Separately, initial reports indicated that Russia had sent additional troops to Crimea. The Ukrainian president's special representative in the southern peninsula, Sergiy Kunitsyn, alleged that Moscow had deployed 2,000 soldiers to a military air base near the capital city, Simferopol.
"Thirteen Russian aircraft landed at the airport of Gvardeyskoye (near Simferopol) with 150 people in each one," Kunitsyn told Ukrainian channel ATR on Friday.
Reports of what Kunitsyn described as an "armed invasion" could not be immediately confirmed.
Meanwhile, the United Security Council began meeting in New York City on Friday to deliberate over the situation in Ukraine.
The Crimean region has been the site of heightened tensions this week, prompted by the dramatic shift in the political landscape in Kyiv after the ouster of President Viktor Yanukovych. Counter rallies between Moscow supporters and ethnic Tatar groups who favor staying under Kyiv's rule became violent on Wednesday. The following day, armed gunmen stormed government headquarters in the Crimean capital city of Simferopol, raising Russian flags over the building. They later declared that Crimea would hold a referendum on May 25 - the same day as elections in Kyiv - to determine its status.
Ukraine regains control of airport
Earlier on Friday Ukraine's new interior minister, Arsen Avakov, accused Russian naval forces of having taken control of the military airport in the Black Sea port of Sevastopol in Ukraine's mainly-Russian-speaking Crimea region.
"I consider what has happened to be an armed invasion and occupation in violation of all international agreements and norms," Avakov said in a statement posted on his Facebook page.
One of Russia's naval fleets is based at Sevastopol.
Later in the morning, dozens of unidentified gunmen were seen patrolling the airport at Simferopol. Officials later said that Ukrainian authorities had regained control of the area. It was not immediately clear when the airport would resume normal operations after the incident prompted flight cancellations.
The heightened tensions prompted both the United Kingdom and Germany to warn their citizens from travelling to or remainining in the Crimean peninsula.
Doubt has arisen since Wednesday over Russia's intentions toward Ukraine, following the announcement of a military drill in the country's vast western region, which borders Ukraine. President Vladimir Putin contends the exercise is not related to the political crisis in the eastern European country and has said Moscow would not infringe on its sovereignty.
Ousted President Yanukovych's sudden reappearance on Friday after disappearing for several days also angered Kyiv. The deposed leader, in clear defiance of an international arrest warrant, gave a press conference in Russia where he insisted that he was still the head of Ukraine. Yanukovych is wanted on mass murder charges in the deaths of nearly 100 people during popular protests.
kms/av (AFP, Reuters)