At least 11 people have been killed and many more wounded after one or more gunmen opened fire in a school in the Russian city of Kazan, the RIA news agency reported on Tuesday.
Two children could be seen leaping from the third floor of the four-storey School Number 175 as gunshots sounded, in a video filmed by an onlooker that was circulated by RIA.
Some Russian news agencies reporting two teenage gunmen were involved and others said a sole shooter took part in the attack.
RIA said a 19-year-old gunman had been detained and that an explosion had been heard at the school.
Footage posted on social media showed a young man being pinned to the ground outside the school building by a police officer.
Footage also showed emergency service vehicles parked outside the school, with people running towards the building.
It was not clear whether any other shooters remained at large. Nor was it immediately clear what the motive for the attack was.
GCC-US talks emphasise regional security, lasting peace
UN agency pauses Hormuz ship evacuation after vessel attacked
164 confirmed dead after two major earthquakes strike Venezuela
Europeans told to protect themselves as deadly heatwave takes its toll
Trump asks Congress for more funds to fight Iran, defying rebuke on war powers
