A mass Russian drone attack killed four people, injured 19 and sparked a large fire late on Friday in the south-eastern Ukrainian city of Dnipro, the regional governor said. Serhiy Lysak, governor of the surrounding Dnipropetrovsk region, said on Telegram that a high-rise apartment building and nearly 10 private homes had caught fire.

Ukraine's SBU security service said on Tuesday it had detained a serviceman it accused of helping Moscow attack Ukrainian troops fighting in Russia's Kursk region by giving away their location. Ukrainian forces crossed the border into the Kursk region last August in a rapid offensive,

At the height of the campaign, Ukrainian forces controlled some 500 square miles of Russian territory. Now they hold just a small sliver of land along the border.