Ukraine’s new government has opened a treason investigation against Rear Admiral Denys Berezovsky, who was named head of Ukraine’s Navy on Saturday, and on Sunday defected to pro-Russian Crimean authorities.

“I, Denis Berezovsky, swear an oath of allegiance to the residents of the republic of Crimea,” Berezovsky said in televised remarks.  “I swear to fulfill my military duty with dignity, to bravely protect lives and freedom of the residents of Crimea and the city of Sevastopol.”

Berezovsky’s big switch came as Russian troops took control of Crimea, a semi-autonomous region of Ukraine, without firing a shot.  Crimea’s newly elected pro-Moscow premier Sergei Aksenov said at the same briefing that he was planning to create a Crimean navy, to be headed by Berezovsky. 

It’s not clear what ships they plan to use or if any more members of Ukraine’s Navy are following Berezovsky.  RT reports at least four more military and security officials defected.