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.

Russia’s summer offensive signals Putin’s determination to overwhelm Ukraine using mass drone warfare, motorcycle assaults, and Chinese tech support, while betting on scale, endurance, and Western hesitancy to act.

Ukraine's top military commander Oleksandr Syrskyi warned on Saturday of a possible new Russian offensive in the Kharkiv region, a part of northeastern Ukraine which has seen heavy fighting since Russia invaded in 2022.