Western countries reacted to the bombing with outrage. UK Foreign Secretary Liz Truss said on Sunday she was “horrified,” adding: “Deliberate targeting of civilians & civilian infrastructure amounts to war crimes. We will ensure Putin’s regime is held accountable.”

Russian forces have struck fleeing or sheltering civilians on numerous occasions since Moscow invaded Ukraine.

Russian forces “must face justice for a series of war crimes” committed in the region northwest of Kyiv, following an investigation it conducted in Ukraine, Amnesty International said Friday.

The investigation, based “on dozens of interviews and extensive review of material evidence,” has documented “unlawful air strikes on Borodyanka, and extrajudicial executions in other towns and villages including Bucha, Andriivka, Zdvyzhivka and Vorzel.”

Fighting in Luhansk has been raging for months, and particularly since Russia refocused its invasion on the eastern Donbas region.

Hayday said on Ukrainian television on Saturday, hours before the school bombing, that the situation was difficult.

“The biggest efforts made by the enemy are to break through in Popasna and the direction of Severodonetsk and Voievodivka. That’s where they deployed the biggest amount of their troops and equipment.

“That’s where the largest number of shellings and rockets, and air strikes are constant — it’s just a terrible situation. Our guys are holding on, we are waiting for help, for reinforcement,” he said.