Dozens of rifle-toting men, many of them masked, were patrolling the parking lot and entrance of the Simferopol airport, news agencies in the Russian-dominated Ukrainian territory reported.
Ukraine's acting interior minister, Arsen Avakov, accused Russian nationalist militants of attempting "an armed invasion and occupation," Russia's RIA Novosti news agency reported, citing Avakov's Facebook page.
Sevastopol airport duty chief Anatoly Rechenko was quoted by UNIAN news agency as saying armed Russian troops were blocking the roads to the military airport, which was closed and its three charter flights scheduled for Friday canceled.
Gunmen representing themselves as "protectors of the Russian people in the Crimea" also appeared on the border between the Crimean republic and mainland Ukraine, a visitor said.
Crimea has become a flashpoint between Ukraine and Russia since an opposition movement last week forced out President
Sevastopol airport was not operating, Avakov said. Civilian flights out of Simferopol were operating normally, Western news agencies reported from the scene at Crimea's main transportation hub.
Acting Ukrainian President Oleksandr Turchynov had warned Thursday that Russian military in Crimea should remain inside their bases to avoid an escalation of tensions on the peninsula.
Ukraine's UNIAN news agency quoted Simferopol airport spokesman
The Russian minority in eastern Ukraine has reacted with alarm at the sudden turnover of political power in the capital, Kiev. A three-month