The report added that 14 children and seven adults were injured in the attack at the No. 88 school located near the city administration building of Izhevsk, the capital city of western Russia's Udmurt Republic, TASS reported.
It was reported earlier that nine people were killed and about 20 others wounded in the shooting.
The shooter has committed suicide and his body has been found, the committee said, adding that he was wearing a black T-shirt with Nazi symbols and a balaclava, and his identity remains unclear as he had no documents with him.
The school has 982 students and 80 teachers, and they have been evacuated.
The governor of the Udmurt Republic declared three days of mourning beginning on Monday.