Ukraine reported the worst shelling in a year in its conflict with pro-Russian insurgents and said it wants a new round of international talks once the warring factions can agree on a lasting cease-fire.

Two soldiers and two civilians were killed as attacks intensified overnight, with the violence concentrated in Avdiyivka, near the separatist stronghold of Donetsk. The government evacuated some of the town’s 22,000 residents after many lost heating and power amid freezing winter temperatures. The fighting, which each side blames on the other, is hindering repairs.