A pro-Russian soldier stands in front of a Russian flag while manning a machine-gun outside an Ukrainian military base in Perevalne, Ukraine. Pic: AP.

SEVASTOPOL, Crimea (AP) — Crimea’s self-defense forces have stormed the Ukrainian navy’s headquarters in the Black Sea port of Sevastopol.

An Associated Press photographer on Wednesday says he witnessed a group of the self-defense forces storm the headquarters and raise the Russian flag on the building.

Russia on Tuesday signed a treaty to incorporate Crimea into its territory following a referendum in which residents of Ukraine’s region overwhelmingly backed the move. Ukraine and the West consider the vote illegitimate.