The Donbass Donetsk club says that a group of "armed men broke into the building" on Wednesday afternoon and "seized" the offices.
In May, the club's arena suffered severe fire damage after being looted by men the club called "bandits" representing the pro-Russian separatist Donetsk People's Republic.
The club did not say whether the armed men involved in Wednesday's incident came from the same group.
Donbass played in the Russia-based Kontinental Hockey League until it withdrew from the competition in the summer because of the damage to its arena.
Last week, the headquarters of Ukrainian champion football club Shakhtar Donetsk were also occupied by armed men.