The fort, now a historical and cultural monument, was damaged when sailors from the Pacific Fleet blew up old shells discovered there.
The fortress of Vladivostok is a unique fortification monument, built in 1889-1914. It was believed to be one of the world's best strongholds in the first decades of the 20th century. The fortress became a museum in 1996.
Fyodorov said the explosions had not been sanctioned calling them "acts of utter vandalism". He said that those involved would be punished.
A rescue squad discovered eight unexploded 122-gauge bombs and a large volume of TNT and hexogen after the explosions.
Rescuers fear the shells and explosives, which may have remained under the ruins, are dangerous to the fort's visitors.