A rare Sukhoi S-70 Okhotnik—the Russian air force’s first stealthy armed drone— got shot down apparently by an accompanying Russian fighter after the drone seemingly malfunctioned near the Ukrainian-held fortress town of Chasiv Yar in eastern Ukraine on Saturday.

Ukraine’s air force said in a statement that air defenses had destroyed 56 of the 87 drones and two missiles over 14 Ukrainian regions, including the capital, Kyiv.

Ukraine on Sunday said it sent more than 100 drones deep inside Russia to hit a major weapons depot, as it stepped up attacks further inside Russian territory.