Interfax later cited Welfare Minister Lyudmila Denisova as saying the officials had been denied entry to Crimea.
At the Ukrainian navy headquarters, an Associated Press photographer said the militiamen took down the gate and made their way onto the naval base. They then raised the Russian flag on the square by the headquarters.
The unarmed militiamen waited for an hour on the square and, following the arrival of the commander of the Russian Black Sea Fleet, they took over the building.
The AP photographer saw the militia roaming around the headquarters while Ukrainian servicemen were packing up and leaving.
On Tuesday, Putin signed a treaty to incorporate Crimea into Russia following a referendum Sunday in which residents of the Black Sea region overwhelmingly backed the move.
Jubilant crowds in Moscow and other cities across Russia hailed the annexation, while Ukraine’s new government called Putin a threat to the “civilized world and international security” and the U.S. and the European Union threatened tougher sanctions against Moscow. On Monday, Washington and Brussels targeted Russian and Crimean officials with visa bans and asset freezes.
Russian news agencies on Wednesday cited Constitutional Court chairman Valery Zorkin as saying the treaty signed by Putin has been ruled valid, thus formally clearing another hurdle for Moscow to annex Crimea. The treaty now only requires ratification by the Russian parliament.
Thousands of troops under apparent Russian command took over Crimea two weeks before Sunday’s hastily called referendum, seizing Ukrainian military bases, blockading others and pressuring Ukrainian soldiers to surrender and leave.
Putin insisted Russia’s military presence in Crimea is legal under a treaty with Ukraine that allows Russia to have up to 25,000 troops at its Black Sea fleet base. Ukraine claims that Russia deployed further forces, however, and expressly went against its request for its troops to remain confined within their barracks.
AP writer John-Thor Dahlberg contributed from Sevastopol, Crimea.