Russian authorities say 15 people have been hurt in a knife incident at a school in the Ural mountains city of Perm.

The local department of the Investigative Committee, a Russian law enforcement agency, says the incident started with a knife fight between two students and that teachers and other students were hurt when they tried to break it up.

The Investigative Committee says it is treating the incident as attempted murder of two or more people.

Of the 15 who were hurt, 12 have been hospitalized, the city health department says.

The regional health ministry adds that a female teacher and two students aged around 15 have been seriously wounded and are in surgery. Nine children received what the department calls "superficial injuries."