The Russian military has unleashed a massive new offensive on the Ukrainian city of Avdiivka, part of its campaign to secure control of the eastern Donbas region. The offensive began with a barrage of missile strikes, followed by a three-pronged ground assault and then the shelling of civilian areas. Avdiivka is a key Ukrainian strongpoint just northwest of the occupied city of Donetsk in the Donetsk and Luhansk regions and a critical gateway to parts of the eastern Donbas that are under Kyiv’s control.

Avdiivka has been the focus of weeks of heavy fighting, with Ukraine battling to keep it from being encircled and captured. But the fighting has escalated, with dozens of people killed or injured.

Russia is trying to encircle the city, which has about 1,500 residents from its pre-war population of about 32,000. The Russians are also advancing on the city’s flanks, hoping to cut supply lines. According to the Institute for the Study of War in Washington, the advance has been accompanied by significant Russian losses, including tanks and armored vehicles.

In a video posted on his Facebook page, Ukrainian Defense Minister Volodymyr Zelensky condemned the “bloodthirsty” attack and called on the international community to provide more weapons and ammunition. “We must do everything to protect Avdiivka and its inhabitants,” he said. “We must prevent the terrorists from getting any supplies and ammunition.”

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Across Ukraine, shelling has been intense. The city of Kherson in southern Ukraine’s Crimea region, which Russia annexed in 2014, has been hit 62 times in the past 24 hours, killing a 64-year-old man and wounding his wife with a skull injury, concussion and shrapnel injuries, a local official said.

Ukraine has also accused Russia of attempting to damage infrastructure. The Ministry of Infrastructure said that in the past two days, six railway stations and two water treatment plants have been hit by missile attacks.

Meanwhile, Russian forces have dropped a nuclear-capable cruise missile on the western Ukrainian port of Berdyansk. The Ministry of Defence said in a statement that the missile was launched from a Russian frigate and reached its target after flying at high speed over the Black Sea.

The ministry didn’t give further details on the attack, and it wasn’t immediately clear if a nuclear warhead was used. The strike came a day after a train carrying a load of grain was derailed in a western Russian town by an explosive device that was hidden on the tracks, damaging 17 railcars.

In other developments, Ukrainian lawmakers called for a winter shield to protect cities and towns from Russian bombardment. They also approved a law allowing the seizure of property belonging to the Russian state-owned energy holding company Gazprom in cases of large-scale violations of the country’s territorial integrity. The move is meant to discourage Russia from continuing its aggression in the east of Ukraine and will be effective as of Dec. 1. The law also requires the Ukrainian government to declare war against Russian armed forces if it fails to take steps to protect its territory.