The situation in Ukraine escalated on Friday, as armed men took over the military airport in the Crimea region.
"Around 400 people are in the airport of Belbek now. They have occupied runway and all plane movements have been stopped," the Interfax news agency reported, citing a local security source.
The Associated Press (AP) reported that at the same time, a convoy of nine Russian armored personnel carriers and a truck were seen on a road between the port city of Sevastopol and the regional capital, Sinferopol.
The Russian tricolor flags were painted on the vehicles, which were parked on the side of the road near the town of Bakhchisarai, apparently because one of them had mechanical problems, the report said.
The Russian Foreign Ministry said movements of armored vehicles belonging to the Russian Black Sea Fleet were prompted by the need to ensure security of its base.
The United States warned Russia not to inflame the situation in Ukraine. The White House said in a statement that Russian intervention in the Ukraine would be a "grave mistake," adding that Ukraine's territorial integrity must be respected.
Speaking at a news conference with the foreign minister of Colombia, U.S. Secretary of State John Kerry said he had raised the issue of the airports as well as reports of Russian armored vehicles and personnel in Ukraine with Russian Foreign Minister Sergei Lavrov.
"While we were told that they are not engaging in any violation of the sovereignty and do not intend to, I nevertheless made it clear that that could be misinterpreted at this moment and that there are enough tensions that it is important for everybody to be extremely careful not to inflame the situation and not to send the wrong messages," Kerry said, according to AP.
Earlier this week Kerry warned Russia that “any kind of military intervention that would violate the sovereign territorial integrity of Ukraine would be a huge – a grave mistake.”
Also on Friday, Ukraine's ousted president Viktor Yanukovych, reappeared a week after he fled Kiev and insisted he had not been overthrown.
Speaking to reporters in the Russian city of Rostov-on-Don, Yanukovych claimed he had been shot at in Kiev and left because of threats to his life, reported AFP.
He vowed to continue to fight for Ukraine's future while boycotting a snap presidential poll the new Western-backed leadership has set for May 25.
"I have not been overthrown by anyone, I was compelled to leave Ukraine due to an immediate threat to my life and the lives of those close to me," he said.
"I intend to continue the fight for the future of Ukraine against those who try to saddle it with fear and terror," added Yanukovych, who called the new leadership "young neo-fascists" and blamed the "irresponsible policies" of the West for the crisis but said he planned to return.
Yanukovych also revealed he had spoken by phone with -- but had not met -- Russian President Vladimir Putin and expressed surprise that his ally had not yet spoken out on Ukraine since his flight.
Ukraine's general prosecutor said Kiev would ask Moscow to extradite Yanukovych, accused of "mass murder" over carnage in the heart of the capital that claimed nearly 100 lives last week and triggered his ouster.
(Arutz Sheva’s North American Desk is keeping you updated until the start of Shabbat in New York. The time posted automatically on all Arutz Sheva articles, however, is Israeli time.)