The base commander of one of the last Ukrainian-controlled airbases was arrested after Russian forces stormed the Belbek airbase in Crimea today, effectively taking over the base, his wife told ABC News.
Base commander Col. Yuli Mamchur's wife said that her husband called her to say he had been arrested and was being taken to a military prison in Sevastopol before the phone line cut out.
His officers told the Russian forces they will not leave the base, which is under Russian control, until he's returned.
Earlier in the day, the Russian forces tried using a tank to overturn a vehicle blocking the main gate of the airbase, which sits on the edge of Sevastopol.
During the initial confrontation shots were fired as troops broke through the wall. At least one person was wounded, according to Mamchur.
"The Russian military is directly responsible for any casualties that its forces -- whether they be regular uniformed troops or irregulars without insignias -- inflict on Ukrainian military members," a senior administration official at the White House said.
"Reports of continued attacks against Ukrainian military personnel and facilities highlight the dangerous situation created by Russia and belie President Putin's claim that Russia's military intervention in Crimea has brought security to that part of Ukraine," the official said. "Russia should immediately begin discussions with the Ukrainian government to ensure the safety of Ukrainian forces in the Crimean region of Ukraine."
In addition to the Belbek airbase, Russian forces seized the Novofedorivka airbase and a Ukrainian submarine. It's unclear what Ukrainian military assets remain in the Ukrainian control.
Before his arrest, Mamchur told ABC News that he spoke to his troops during the earlier standoff, telling them not to surrender but also not to fight. At the time, Russian troops encircled the airbase but kept their weapons down.
While talking to his troops, Mamchur said Ukrainians were going to turn over their weapons. Media outside the base was later moved away from the front gate by Russian forces and had some equipment confiscated.
ABC News' Dragana Jovanovic and The Associated Press contributed to this report.