|Viktor Yanukovych, the President of Ukraine went missing days ago.
Armed men seize two airports in Ukraine's Crimea, Russia denies involvement
Armed men took control of two airports in the Crimea region on Friday in what Ukraine's government described as an invasion and occupation by Russian forces, raising tension between Moscow and the West.
Russia's Black Sea fleet, which is based in the region, denied its forces were involved in seizing one of the airports, Interfax news agency reported, while a supporter described the group at the other site merely as Crimean militiamen.
Amid the confusion over the men's identity, acting president Oleksander Turchinov called an emergency session of his security chiefs, while parliament urged Moscow to halt any action that might encourage separatism and asked the United Nations Security Council to discuss the crisis.
Tensions have been rising on the Black Sea peninsula, the only Ukrainian region that has an ethnic Russian majority and the last major bastion of resistance to the overthrow of Viktor Yanukovich as president almost a week ago.
Interior Minister Arsen Avakov accused Russian naval forces of taking over a military airport near the port of Sevastopol, where the Black Sea fleet has its base, and other Russian forces of seizing Simferopol's civilian international airport.
Armed men seize Crimea government HQ in Ukraine Play video
Armed men seize Crimea government HQ in Ukraine
"I consider what has happened to be an armed invasion and occupation in violation of all international agreements and norms," Avakov said on his Facebook page, describing it as a "provocation" and calling for talks.
This met with a Russian denial of involvement in the military airport action. "No Black Sea Fleet units have moved toward (the airport), let alone taking any part in blockading it," Interfax quoted a spokesman for the fleet as saying.
Yanukovich is expected to appear before reporters in the Russian city of Rostov-on-Don later on Friday, though President Vladimir Putin has not said whether Moscow will harbor the former leader, who is on the run and wanted by the new government for mass murder after the deaths of protestors in Kiev last week.
The United States has told Russia to show in the next few days that it is sincere about a promise not to intervene in Ukraine, saying using force would be a grave mistake.
"We believe that everybody now needs to take a step back and avoid any kind of provocations," U.S. Secretary of State John Kerry told a joint news conference with German Foreign Minister Frank-Walter Steinmeier. "We want to see in the next days ahead that the choices Russia makes conform to this affirmation we received today."