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Ukrainian Interior Minister Arsen Avakov said early Friday that Russian forces have seized control of two airports in the southern province of Crimea, where Russia has several military bases, including the home port for its Black Sea naval fleet. The airports, Simferopol International Airport in the provincial capital and a military airport in Sevastopol, were taken with no shots fired by armed men in unmarked camouflage who "do not hide their affiliation," he said on Facebook.

"I consider what has happened to be an armed invasion and occupation in violation of all international agreements and norms," Avakov added. He called for a negotiated end to the standoff. --Peter Weber