Ukraine has said it destroyed two bridges inside Russia by using a couple of cheap drones to hit stashes of mines and ammunition hidden there by Russian forces.

The Ukrainian military said the two bridges near the border with Ukraine’s Kharkiv region were being used by the Russian military to resupply their troops.

Because of their strategic importance, the bridges were mined – so that the Russian military had the option of blowing them up in case of a sudden Ukrainian advance.

It is not unusual for an army under attack to destroy bridges, roads and other key infrastructure on its own territory to prevent the enemy from advancing. Ukraine did this in the early days of the full-scale invasion in February 2022, destroying bridges on roads leading towards Kyiv. The move delayed the Russian advance and protected the Ukrainian capital.

In the case of the two bridges in Russia, the Ukrainian military found out about the stashes of mines and used it to its own advantage.