Russian forces fired cruise missiles at the southern Ukrainian city of Odesa and shelled the eastern Donetsk region early on Wednesday, killing at least six people and damaging dozens of homes, regional Ukrainian officials said.

Russian forces have stepped up aerial strikes in their nearly 16-month war, a Ukrainian military spokesman said, while the country’s armed forces have reported limited gains in the early stages of a counteroffensive to take back the nearly one-fifth of Ukraine’s territory that is under Russian control.