Damage at Air Base in Crimea Worse Than Russia Claimed, Satellite Images Show

Russian forces killed at least 13 civilians and wounded 11 others in an overnight missile attack in southern Ukraine, a senior Ukrainian military official said on Wednesday, in an escalation of fighting around a key nuclear power plant held by Moscow.

The Russians used Grad missiles in the attack on the Nikopol district, across the Dnipro River from the Zaporizhzhia Nuclear Power Plant, according to the head of the Dnipropetrovsk military administration, Valentyn Reznichenko. He said that Russians had fired 80 rockets on residential neighborhoods, causing damage to apartment blocks, administrative buildings and infrastructure, and leaving 1,000 people without gas.

Russian forces launched a “deliberate and insidious strike when people were sleeping in their homes,” Mr. Reznichenko wrote on the Telegram social messaging app. He said that 10 residents were hospitalized, seven of whom were in serious condition.

In his nightly address on Wednesday, President Volodymr Zelensky said Ukraine would not leave the “Russian shelling of the Dnipropetrovsk region unanswered.”

In recent weeks, Russia has reinforced its positions in Kherson Province, which borders Dnipropetrovsk, and targeted a series of missile attacks there and on nearby provinces. According to Ukrainian officials, those attacks have included shellfire directed at Nikopol from the Zaporizhzhia plant, which Russian forces seized in March soon after invading Ukraine in February.

It was not clear whether the overnight attack had come from the grounds of the nuclear plant. On Saturday, rocket fire struck a dry spent-fuel storage facility at the plant itself. Ukraine and Russia blamed each other for the episode, which prompted the head of the United Nations’ nuclear watchdog, Rafael Mariano Grossi, to express “grave concern” and renew his appeals for a formal inspection of the plant.

The Ukrainian authorities, as well as independent military and nuclear experts, say that the transformation of the plant, the largest in Europe, into a combat zone is almost without precedent. They also say that Russia’s use of the site as a base from which to launch attacks offers a tactical advantage, given that it is extremely difficult for Ukraine to return fire without imperiling the plant’s reactors.

Fighting in the south is intensifying as Ukrainian forces receive an influx of long-range artillery from the United States and other Western countries, increasing its capacity to strike Russian military infrastructure far behind the front lines. A Ukrainian official said that Ukrainian forces were responsible for a blast on Tuesday at a Russian air base on the western coast of Crimea, the peninsula that Moscow illegally seized in 2014, but said that a domestically manufactured weapon had been used in…