In the north a 50,000-strong Russian force is attacking Sumy, a provincial capital. Our model is detecting artillery fire and explosions along the city’s northern defensive lines. Ukraine is badly outnumbered but officials say the front is holding.

The Ukrainian air force said it had downed 319 Shahed drones and 25 missiles, adding that one missile and about 20 drones hit “five locations”. Zelensky said the strikes had killed at least two people and wounded 20 in the southwestern Chernivtsi region, far from the front lines of the east and south.

Russia fired 597 drones and decoys, along with 26 cruise missiles, into Ukraine overnight into Saturday, Ukraine’s air force said. Of these, 319 drones and 25 cruise missiles were shot down and 258 decoy drones were lost, likely having been electronically jammed.