At least nine people have been killed and 20 injured in a school shooting on Monday in the Russian city of Izhevsk, 600 miles east of Moscow, according to Russian authorities.

A gunman entered School Number 88, which teaches the first to 11th grades, and killed two security guards, two teachers and at least five minors, according to federal investigators, who also said the assailant killed himself.

According to the Investigative Committee, Russia’s top federal investigative authority, the attacker “was wearing a black top with Nazi symbols and a balaclava” and was not carrying any ID.

“His identity is currently being established,” investigators said.

The shooting came on the same day a gunman opened fire at a Siberian military enlistment center, injuring a recruitment officer, as anger mounted over President Vladimir V. Putin’s plan to mobilize hundreds of thousands of civilians to bolster Russia’s struggling army in Ukraine.

However, there appeared to be no link between the shooting at the school and the conflict in Ukraine.

In the past three years, there have been at least 13 mass shootings in Russia, including a school shooting in Kazan in May 2021 that resulted in nine deaths and 23 casualties.

Izhevsk, population 630,000, is the regional capital of the Udmurt Republic. The regional governor there, Aleksandr Brechalov, declared three days of mourning.