“Found these in the Zaporizhzhya direction. The enemy is throwing chocolates with an explosive mechanism. Do not open them under any circumstances. Our guy was lucky that it did not detonate, otherwise he could have ended up crippled. I know guys whose fingers were torn off like that.”
Might even be passive, a tuned resonator. Heck it could be a bug, IIRC ironically passive bugs are (age-old) soviet tech. Imagine sweeping the whole frequency spectrum for resonators with 50s tech they were a nightmare to screen for.
Maybe the idea is to track people for some time to gather intelligence on trench operations? Most probably aren’t going to eat the thing right away.