The mayor of Kyiv, Ukraine’s capital, has warned residents that if Russia continues to strike the country’s energy infrastructure, they must brace themselves for the worst this winter, which means no electricity, water, or heat in the bitter cold.

“We’re doing everything we can to avoid this.” But, let’s be honest, our enemies are doing everything they can to keep the city without heat, electricity, or water, so that we all perish. And how prepared we are for different situations determines the future of the country and each of us,” Mayor Vitali Klitschko told state media.

Over the last month, Russia has targeted Ukraine’s energy infrastructure, causing power outages and rolling blackouts across the country. Kyiv was scheduled to have hourly rotating blackouts Sunday in parts of the city and the surrounding region.

Ukrenergo, Ukraine’s state-owned energy operator, said rolling blackouts were also planned in the nearby Chernihiv, Cherkasy, Zhytomyr, Sumy, Kharkiv, and Poltava regions.

Kyiv intends to install about 1,000 heating points, but this may not be enough for a city of 3 million people.

As Russia intensifies its attacks on the capital, Ukrainian forces advance southward. Residents of Ukraine’s Russian-occupied city of Kherson received text messages urging them to evacuate as soon as possible, according to Ukraine’s military. Russian soldiers warned civilians that Ukraine’s army was preparing a massive attack and advised them to flee immediately to the city’s right bank.

Russian forces are preparing a counteroffensive in Ukraine to retake the southern city of Kherson, which was captured early in the invasion. Russia illegally annexed Kherson and three other Ukrainian regions in September, declaring martial law in the four provinces.

The Kremlin-installed administration in Kherson has already relocated tens of thousands of civilians.

Russia has been “occupying and evacuating” Kherson at the same time, convincing Ukrainians that they are leaving when, in fact, they are digging in, according to Nataliya Humenyuk, a spokeswoman for Ukraine’s Southern Forces.

Russian forces are also digging in in a hotly contested region in the east, making life even more difficult for residents and the defending Ukrainian army in the aftermath of Moscow’s illegal annexation and declaration of martial law in Donetsk province.

According to Pavlo Kyrylenko, the region’s Ukrainian governor, the attacks nearly completely destroyed the power plants that serve Bakhmut and the nearby town of Soledar. He reported late Saturday that shelling killed one civilian and injured three others.

Before Russia invaded Ukraine in late February, Moscow-backed separatists controlled a portion of Donetsk for nearly eight years. One of Russian President Vladimir Putin’s justifications for the invasion was to protect the separatists’ self-proclaimed republic there, and his troops have spent months attempting to capture the entire province.

While Russia’s “greatest brutality” was concentrated in the Donetsk region, “constant fighting” continued elsewhere along the 1,000-kilometer-long front line, Ukrainian President Volodymyr Zelenskyy said in his nightly video address.

According to the president’s office, Russia launched four missiles and 19 airstrikes between Saturday and Sunday, striking more than 35 villages in nine regions ranging from Chernihiv and Kharkiv in the northeast to Kherson and Mykolaiv in the south. According to the office, the strikes killed two people and injured six others.

According to local media, 15,000 people in the Donetsk city of Bakhmut were subjected to daily shelling and were without water or power. The city has been bombarded for months, but the bombardment increased after Russian forces suffered setbacks during Ukrainian counteroffensives in Kharkiv and Kherson.

DNA samples have been collected from 450 bodies discovered in a mass grave in Izium, but the samples must be matched with relatives, and only 80 people have so far participated, he said.

The Zaporizhzhia Nuclear Power Plant was reconnected to Ukraine’s power grid on Sunday, according to local media. The world’s largest nuclear power plant requires electricity to keep vital cooling systems running, but it has been running on emergency diesel generators since Russian shelling cut off its outside connections.