The attack took place in a secondary school in Ural mountains city of Perm, Xinhua news agency reported, quoting the regional Health Ministry.
"The teacher and two students aged 15 and 16 are in grave condition, and are undergoing surgery," a Ministry statement said, adding that other wounded have been provided with medical care.
Two pupils started the knife fight, the regional division of the Investigative Committee said in a separate statement.
Educational activity in the school has been suspended with all pupils and teachers evacuated, it said, adding that suspects have been detained and will be interrogated.
The Investigative Committee has initiated a criminal case on the grounds of attempted murder of two and more persons.
(This story has not been edited by Social News XYZ staff and is auto-generated from a syndicated feed.)
