Stoltenberg did not give any details. Russia was recently accused of using so-called thermobaric artillery weapon systems, which cause a particularly destructive combination of heat and pressure waves.
Cluster munitions are rockets or bombs that burst while still in the air over the target, releasing a large number of small explosive devices, the so-called submunitions. These mini-bombs, about the size of a soda can or aerosol can, then fall to the ground within a radius of several tens of meters.
They can penetrate even lightly armored vehicles and not only fatally injure people nearby with their fragmentation effect. Cluster munitions can be fired from the ground by rocket launchers, but they can also be dropped as bombs from aircraft.