A stun grenade injured four teachers in the Moscow region on Tuesday during a counter-terrorism exercise mishap, according to Russian media reports.
Independent Russian outlet Astra, citing reports from various Russian outlets, said the incident took place at School No. 21 in the village of Serkovo in the Moscow region.
The grenade was reportedly thrown through a window, landed on a table and exploded, causing eye injuries and abrasions to four teachers.
Russian outlet Baza said the grenade “struck a wooden beam” and the teachers were “injured by splinters from the explosion.” The outlet added that three were hospitalized but have subsequently been released.
Baza said the incident took place during “nationwide anti-terrorism training exercises,” while Russian outlet Nova Gazeta Europa noted that the exercises start on Tuesday and are set to last for two days across kindergartens in Russia.
The outlets did not name the Russian law enforcement agency involved.
One kindergarten reportedly said the exercises involve scenarios such as hostage taking and “armed attack using flammable liquids,” according to Nova Gazeta Europa.
The outlet noted that similar exercises were held on a small scale in 2024 but have since expanded to hundreds of Russian schools, kindergartens, colleges, and children’s camps by 2025.
School shootings are relatively rare in Russia compared to the US, with the last known case taking place in May 2026, when a teenager injured two students with an air pistol in Russia’s Krasnodar Krai.
The last major terrorist attack took place in March 2024, when the Islamic State (IS) staged a shooting in Moscow’s Crocus concert hall that claimed over 100 lives. Moscow attempted to frame Kyiv for the attack in its aftermath despite IS officially claiming responsibility.
The most infamous terrorist attack in Russia involving a school, known as the Beslan school siege, took place on Sept. 1, 2004, in the Caucasian mountains’ Ossetian Republic.
The three-day siege ultimately resulted in a shooting that killed 334 people, including 186 children and 31 attackers, making it the deadliest school shooting in history.