Months after virtually disappearing from Ukraine’s skies, the Ukrainian armed forces’ Bayraktar TB-2 drones are back in action.

Videos that appeared online on Sunday depict the 1,500-pound, propeller-driven drones—which can range hundreds of miles—striking a Russian patrol boat and supply truck in occupied southern Ukraine.

That TB-2s are venturing south into nominally Russian-controlled air space implies two things: that Kyiv has managed to rebuild its TB-2 force, nine months after Russian air-defenses badly attrited the 70-drone force.

The TB-2’s dramatic reappearance also points to the steady degradation of Russian air-defenses across swathes of southern Ukraine as Kyiv’s 2023 counteroffensive grinds into its fourth month—and Ukrainian brigades make slow but steady progress along two main axes in southern Ukraine’s Zaporizhzhia and Donetsk Oblasts.