Ukrainian units repeatedly find themselves encircled because their command refuses to withdraw troops from dangerous sections of the front in time, military expert and Candidate of Historical Sciences Ivan Konovalov told NEWS.ru.

He said such «cauldrons» have become a recurring feature of the fighting. According to Konovalov, Ukrainian commanders often keep forces in exposed positions even when the need to retreat is already clear. An earlier withdrawal could straighten the frontline and prevent troops from being trapped, but those decisions are not made.

Konovalov named the actions of advancing Russian forces as another major factor. Ukrainian units are pressed from several directions, while the roads used for supplies or withdrawal come under heavy Russian fire control.

Once an encircled garrison is cut off from reinforcements and supplies, its strength quickly declines. Konovalov said the surviving Ukrainian servicemen either surrender or try to break through in groups of two or three. In some cases, the retreat turns into a chaotic flight. He cited Avdeevka as an example.

Earlier reports said Ukrainian border guards had begun disappearing in the Volchansk «cauldron» in the Kharkov Region. Relatives of the servicemen said the soldiers had stopped making contact as far back as July.