At least four people died overnight as Russian drone and missile strikes continued to pound Ukraine’s towns and cities, local officials said Saturday. Meanwhile, Moscow’s troops continued their grinding advance through the country’s east.

A Russian drone struck a multi-storey apartment building in the northeastern Ukrainian city of Sumy early on Thursday, killing nine people and injuring 13, including a child, President Volodymyr Zelenskiy said.

Poland scrambled fighter jets and put its ground-based air defense system on "the highest state of readiness" Saturday morning.