Shots were fired as pro-Russian troops broke through concrete walls and forced their way into a Ukrainian air force base in the Crimean city of Belbek on Saturday.
According to Reuters, the base’s Ukrainian commander Col. Yuily Mamchur said a serviceman was injured when the unmarked troops entered the facility.
Ukraine’s Defense Ministry spokesman Vladislav Seleznev wrote on Facebook that these troops were members of recently formed local militias.
Russian forces also stormed a base about 30 miles west of Simferopol on Saturday, according to Ukraine’s Defense Ministry. Ukrainian troops reportedly attempted to keep them at bay with smoke grenades.
Saturday’s events come after Russian troops took over multiple Ukrainian military facilities in Crimea during the past week. Sanctions from the United States and E.U. have failed to deter Russia in its plans to annex the region.
Russia has also moved more troops to the border with eastern Ukraine where protests have grown over the idea of holding a referendum about whether or not to leave Ukraine and join Russia.
A rally in the eastern Ukrainian city of Donetsk on Saturday drew 5,000 pro-Russian supporters.
A team of observers from the Organization for Security and Cooperation in Europe (O.S.C.E.) will be deployed, but questions remain as to whether they will be allowed into Crimea.
The O.S.C.E’s chief U.S. envoy Daniel Baer said the team should be able to enter Crimea because it is still part of Ukraine, while Russia’s Foreign Ministry spokesman Alexander Lukashevich said the O.S.C.E. mission would not cover Crimea and Sevastopol as they are part of Russia.