Russia's National Anti-Terrorist Committee says 10 police officers were killed and 28 wounded in gun battles with militants in the capital of Chechnya.

The leader of the Russian republic announced that at least nine of the militants were killed before the fighting ended.

The gun battles left a 10-story building and a school in ruins in the center of the Chechen capital, Grozny.

The fighting early Thursday punctured the patina of stability ensured by years of heavy-handed rule by the Kremlin-appointed leader.

The violence erupted hours before Russian President Vladimir Putin gave his annual state of the nation address.