Ukraine's interim interior minister says Russian forces have taken control of the two main airports in Ukraine's Crimea region, in one of several reported actions by the Russian military on the peninsula Friday.
Interior Minister Arsen Avakov described the development as a "military invasion" in a Facebook post Friday. He said armed Russian troops were blocking the Belbek airport in Sevastopol, where Russia has a naval base. The press service of Russia's Black Sea Fleet, which is based in Crimea, denied that any of its units were involved in blocking the airport.
Unidentified gunmen were also patrolling the international airport in Simferopol, the Crimean capital.
A VOA correspondent who flew into Simferopol Airport on Friday saw gunmen wearing camouflage and carrying automatic weapons at the airport. She described the situation as calm and said flights were still arriving and the airport remained open.
"I saw about a dozen people in what looks like unbranded military uniforms - very, very professional, with extremely modern, heavy weaponry that they were carrying. But they had no insignia, nothing to identify them, other than by their demeanor and their dress and their weaponry. Professional soldiers: these are not sort of the self-defense units that we've seen in Kyiv or are here in other parts of Crimea. But again, it's a mystery who these people are. They are not a menacing presence: the airport is open, flights are coming in and they are not bothering anybody."
Meanwhile, the Associated Press quoted Ukraine's State Border Guard as saying a Ukrainian coast guard base was surrounded by about 30 Russian marines.
Ukraine's border guard service also said Friday that more than 10 Russian military helicopters flew into Ukrainian airspace over Crimea. Ukraine's UNIAN news agency and other media posted what they said was a video of the flyover.
Ukrainian media also reported Friday that armed persons were blockading the premises of Krymaerorukh (CrimeaAeroMovement), a state enterprise responsible for controlling air traffic over Crimea.
Ukraine's Interim President Oleksandr Turchnyov called an emergency session of his security chiefs Friday to discuss the situation. Ukraine's parliament also urged Russia to respect its territorial integrity.
The events come a day after gunmen seized control of government buildings in Crimea, a Ukrainian region with strong ties to Moscow. Those gunmen raised the Russian flag over the buildings on Thursday.
Late Thursday, U.S. Vice President Joe Biden telephoned Ukraine's interim Prime Minister Arseniy Yatsenyuk to welcome the formation of a new government and pledge U.S. support as Ukraine undertakes reforms aimed at restoring the country's economic health. Ukraine's parliament approved Mr. Yatsenyuk, a popular, pro-Western opposition leader, as the head of the interim government earlier in the day.
Mr. Yatsenyuk has accused the Yanukovych government of stealing billions from the state treasury. He said $70 billion in Ukrainian government money had been sent to offshore accounts over the last three years, and that $37 billion of credit it received has disappeared, leaving Ukraine with severe financial problems.
Judicial authorities in Geneva on Friday launched a probe into the allegations of money laundering by Mr. Yanukovych and by his son. The Swiss government has also announced it is freezing the assets of 20 Ukrainian officials.
The International Monetary Fund and European Union are sending teams to Ukraine to assess the country's needs. The United States also is considering $1 billion in loan guarantees.
Also Thursday, the Kremlin sent Russian fighter jets to patrol its border with Ukraine -- a day after announcing large-scale military exercises in the area.
Acting Ukrainian President Turchynov warned that any movement of Russian forces outside their base in the region would be considered "military aggression."
The Crimean parliament voted Thursday to dismiss the regional government and hold a referendum to determine Crimea's status in Ukraine. The referendum is set for May 25, the same day Ukraine will hold a presidential election.