At least four people were killed overnight and on Saturday morning as Russia continued to pound Ukraine with hundreds of drones and cruise missiles as part of a stepped-up bombing campaign that has further dampened hopes for a breakthrough in efforts to end the more than three-year-old war.

Russia fired 597 drones and decoys, along with 26 cruise missiles, into Ukraine overnight into Saturday, Ukraine's air force said.

Hundreds of Russian attack drones and more than two dozen cruise missiles targeted Ukraine overnight, killing at least two people, Ukraine said.