Russia's Investigative Committee is looking into the incident in a school in Sterlitamak, Bashkortostan Region.
"According to preliminary information, a 17-year-old student of a special class at general education school number 1 in the city of Sterlitamak entered a computer science room where his schoolmates were staying and wounded a schoolgirl in the hand, as well as a teacher, with a knife," the Investigative Committee said in a report. He then spilled combustible substance and set it on fire. "He wounded himself with a knife," the Investigative Committee said.
Another schoolgirl was scared and jumped out of a window on the second floor. Two victims and the teenager himself were taken to hospital.
"The fire alarm system went off in the school. No one was injured in the fire," TASS cited the committee as saying.
Investigators are working on the site. The issue of launching a criminal case is pending.
It was earlier reported that four people have been taken to hospital after the attack.
