Crimea's self-defense forces on Wednesday stormed the Ukrainian navy base in the Black Sea port of Sevastopol a day after Russia signed a treaty with local authorities to annex the region.

An Associated Press photographer witnessed several hundred self-defense forces take down the gate and make their way onto the headquarters' premises. They then raised the Russian flag on the square by the headquarters.

Ukrainian servicemen were standing guard by the main building. Crimean self-defense forces are not armed and seemed to be waiting for the Ukrainian army's decision whether to let them in.

On Tuesday, Ukraine authorities authorized soldiers to shoot in self-defense after an officer was killed when gunmen attacked a besieged military base near the capital of Crimea, according to news reports.

The shooting came hours after Russian President Vladimir Putin and Crimean leaders signed a treaty that makes the Black Sea peninsula part of the Russian Federation, a move the White House and European leaders called an illegal annexation. Residents of Crimea voted Sunday to secede from Ukraine.

The soldier's death was the first since Russian troops took control of Crimea in February after pro-Moscow President Viktor Yanukovych fled Ukraine following deadly mass protests over his decision to scrap closer ties with the European Union.

A witness told the BBC that armed men got out of two unmarked vehicles outside Simferopol and stormed the mapping facility, firing automatic weapons. A junior officer manning a tower was killed, along with a Crimean self-defense force member, the Interfax News Agency reported. Another Ukrainian officer was wounded in the neck.

The attackers detained other soldiers, who wore Russian uniforms, the Ukrainian News Agency reported, citing a defense ministry official.

A pro-Russian news outlet created by Crimean authorities gave a different account, claiming snipers fired on the base and on self-defense forces checking a report of armed men at the facility. One self-defense brigade members was also killed, a police spokesman told Interfax.

"The conflict is moving from a political one to a military one because of Russian soldiers," Ukrainian Prime Ministe Arseniy Yatsenyuk said at the defense ministry. "Today, Russian soldiers began shooting at Ukrainian servicemen and this is a war crime without any expiry under a statute of limitations."

Acting President Aleksandr Turchinov authorized Ukrainian troops in Crimea to use firearms to "defend their lives" after the shooting.


Contributing: Associated Press