The Russians used stun grenades and fired automatic weapons as they charged in, a Ukrainian military official said. Ukrainian flags had been taken down from flagpoles inside the base.
Ukrainian army officer, First Lieutenant Anatoly Mozgovoy, told Reuters by phone from inside the compound that the Russians had fired shots and the Ukrainian soldiers were unarmed. Asked if the base had been taken over, he said: "Yes".
"The invading troops were using stun grenades and also firing automatic weapons. The interior of the compound is full of Russian troops," said Vladislav Seleznyov, a Ukrainian military spokesman in Crimea.
Russian forces had already captured part of the base, used by the 1st Separate Marine Battalion, Ukraine's top military unit, earlier this month.
By Aleksandar Vasovic