The alleged shooter was arrested, the state news agency RIA Novosti reported, citing a law enforcement agency.
Svetlana Petrenko, an official representative of the Russian investigative committee, was quoted by the TASS news agency as saying that an armed young man was arrested after breaking into a school. Petrenko added that his identity has been established and that he is a local resident born in 2001.
TASS initially reported that two attackers were involved in the incident, but later quoted the head of the press service of the President of Tatarstan as saying there was only one shooter.
TASS also reported that the investigative committee opened a case of mass murder following the shooting. The RIA had previously quoted an ambulance service source as saying that at least nine people had been killed.
Kazan is the capital of the Republic of Tatarstan, a federal Russian region. Pictures from the area showed armed Federal Security Service (FSB) officers storming the school building while the area was cordoned off with police tape.
Witnesses also reported to state media that an explosion had occurred during the attack prior to the shooting, although it was not immediately clear what caused the explosion. Several children jumped out of the school window to flee.
“There is heavy smoke,” an emergency services source told the RIA.
21 ambulance teams and doctors were sent to the school in Kazan.
Russian President Vladimir Putin was informed of the incident by FSB director Alexander Bortnikov, according to Kremlin spokesman Dmitri Peskov. Putin expressed his condolences to the families of the victims of the incident.
Peskov also told journalists that Putin had asked the head of the Russian National Guard Viktor Zolotov to “urgently” develop new weapons control measures that would regulate the types of weapons that may belong to civilians. The National Guard is an internal Russian security force.
A plane from the Ministry of Emergency Situations with doctors, equipment and psychologists had been sent to Kazan, Peskov said, adding that Russian ministers of health and education were also on their way to the city.
According to TASS, security measures have been strengthened in all educational institutions in Kazan. The mayor’s office also said access to schools was limited.