MOSCOW, April 24. /TASS/. A grenade that killed one teenager and wounded 11 more at a school in Russia’s North Caucasian republic of Dagestan was brought to school by a schoolboy, a spokesman for the Dagestani Interior Ministry told TASS on Monday.

"According to verified information, a hand grenade went off in an IT room of a secondary school. It was brought by a schoolboy," the spokesman said, adding that an investigation is underway.

The spokesman said the explosion occurred due to mishandling of the grenade. The incident took place in a secondary school in the settlement of Agvali. 

Ten teenagers were taken to hospital after the incident, three of them are in a serious condition, a spokeswoman for Dagestan’s Health Ministry told TASS.

She said that the most seriously wounded teenagers might be airlifted by an Emergencies Ministry’s plane for further treatment in Dagestan’s capital city Makhachkala.

"Investigators accompanied by psychologists have been working with the teenager who brought a grenade to school," the press service of the Russian Investigative Committee told TASS.

"The boy says he found the grenade in the street," the press service added.