Russian forces used the “Easter truce” as a cover to improve front-line positions, according to Ukrainian soldiers.

Ukraine’s Khartiia Brigade warned Russia was using the “ceasefire” to increase personnel in Kharkiv, while a separate Ukrainian army unit said the Russians on Sunday were “preparing routes for the passage of heavy equipment” across the Black Stallion River in Luhansk.

The 66th Separate Mechanised Brigade added that Russian troops had launched drone strikes against its positions, and that Ukrainian aerial reconnaissance had spotted machine guns being moved towards the front line.

Vladimir Putin ordered the 30-hour temporary truce on Saturday, in what would have been the most significant pause in the fighting throughout the three-year conflict.

The Russian dictator said his forces would “stop all military activity” between 6pm Moscow time and midnight on Sunday. Kyiv also agreed to adhere.