A Russian strike on a regional government building in the southern Ukrainian port city of Mykolaiv on Tuesday destroyed a large portion of the building and left at least 11 trapped in the rubble, according to the region’s governor.

The government building is the latest to be hit as Russian forces have destroyed locations seen as symbols of Ukrainian statehood.

Mykolaiv is nestled along the Black Sea coast, at a strategic junction between the city of Odessa — the headquarters of the Ukrainian navy and the country’s largest civilian port — and the Crimean Peninsula, which Russia annexed in 2014. The city has been under heavy siege by Russian forces since the start of the invasion, but Russian forces have not been able to take control there.

Vitaly Kim, the governor of Mykolaiv, said in a series of video posts on Tuesday morning at the site of the attack that dozens of people had managed to flee from the building before it was hit. There were reports of air raid sirens in Mykolaiv on Tuesday morning.

Kim said that Russian forces had struck after people arrived for work, but that he had overslept — and was lucky not to have been in his office.

New York Times News Service