Pro-Russian activists have entered a Ukrainian naval base in Crimea, a day after two people were killed and two others injured as the result of earlier violence at another base in the region, news reports said.
Several serviceman were seen leaving Ukraine's naval headquarters in Sevastopol after about 200 pro-Russian activists stormed the base and raised the Russian flag, though no shots were said to have been fired, the BBC reported Wednesday, citing a Ukrainian officer.
The base takeover follows violence at a Ukrainian military base in the Crimean capital of Simferopol on Tuesday, when the Ukrainian Defense Ministry said a soldier was killed after coming under attack by a group of men wearing Russian uniforms, Reuters reported.
A further death was reported Tuesday in an online statement by the Crimea police, who said a "self-defense soldier" was shot and killed, and two others injured.
The deaths mark the first from conflict since troops thought to be Russian took control of Crimea in the run up to a regional referendum in which more than 96 percent of voters cast ballots in favor of secession from Ukraine. On Tuesday, President Vladimir Putin signed a treaty agreeing to annex the Black Sea peninsula to Russia.
The Crimean police statement said the shots were fired from a sniper rifle and that "similar tactics were used during the mass riots on the Maidan in Kiev," referencing the protest movement that led pro-Western authorities taking power in the Ukrainian capital.
The Crimean Interior Minister has since said that the shooter was a 17-year-old from the western Ukrainian city of Lviv suspected of being part of the ultranationalist Right Sector group, The Guardian's Shaun Walker wrote on his Twitter account.
Russian media have repeatedly reported on the threat from nationalist Maidan activists and Crimean authorities have asked for protection from Russia, though until this point tension between pro-Ukrainian and pro-Russian sides had not turned to violence.
In the aftermath of the shootings Tuesday Ukrainian Prime Minister Arseny Yatsenyuk said Russia had committed a "war crime" and that the conflict had moved to a "military phase." The Ukrainian Defense Ministry, which had previously urged restraint for its soldiers, said it would allow its forces to use their weapons for self-defense.
Kremlin spokesman Dmitry Peskov told the BBC that after the annexation Ukrainian soldiers could either join the Russian army or "be free to leave the peninsula."
Acting Ukrainian Defense Minister Ihor Tenyukh said Wednesday morning that Ukrainian forces would not withdraw from Crimea.