Officials say a Russian drone has blasted a hole in an apartment building in northeastern Ukraine during a nighttime attack, killing at least four people and injuring nine others.

A Russian drone attack on a residential block killed eight people including three elderly couples in the eastern Ukrainian city of Sumy, prosecutors said on Thursday. Moscow has pummelled Ukrainian cities with dozens of drones or missiles almost daily since it invaded in early 2022.

Four Ukrainian drones hit Russia's Lukoil refinery early Wednesday morning causing fires and significant damage, according to Ukraine's military intelligence. It comes days after Russia's Ryazan oil refinery was hit.