INTERNATIONAL: "How much explosives do you think will fit in this one?," a Ukrainian bomb disposal serviceman asks the class of students in Kyiv, holding up a fluffy toy owl in front of them.

The youths were attending emergency drills being held at their school after a slew of hoax bomb threats that forced the evacuation of schools in several Ukrainian cities this year .

The fluffy owl could hold a kilogram of explosives, enough to kill anyone within five metres and wound people up to 15 metres away, the senior inspector of the de-mining unit, Oleksandr Shcherbyn, has told the silent teenagers.

He has showed the class video clips of explosions blowing up buildings or throwing off deadly shrapnel and demonstrated how to recognise improvised explosive devices.

"Everyone should understand the mechanics of possible reactions in case of a similar situation," his colleague from Ukrainian State Emergency Service has told them.

As the alarm went off in the school, everyone rose to evacuate, 365 children aged from 6 to 16 years, lining up on the snow-covered school yard.

The Ukrainian authorities blame Russia for the increase of hoax bomb threats, saying that it's "part of a hybrid warfare".

The Ukrainian security service has said it recorded more than 300 false bomb threats so far this year, compared to 1,100 in the whole of 2021.

Russian officials have blamed Ukraine for a similar series of hoax bomb threats which have forced Russian schools, shopping centres and kindergartens to evacuate tens of thousands of people.