KYIV, Ukraine — Russian forces are raising “true hell” in Ukraine’s eastern industrial heartland, despite assessments they were taking an operational pause, a regional governor said Saturday, while another Ukrainian official urged people in Russian-occupied southern areas to evacuate quickly “by all possible means” before a Ukrainian counteroffensive.

Deadly Russian shelling was reported in Ukraine’s east and south.

The governor of the eastern Luhansk region, Serhyi Haidai, said Russia launched over 20 artillery, mortar and rocket strikes on the region overnight and its forces were pressing toward the border with the Donetsk region.

“We are trying to contain the Russians’ armed formations along the entire front line,” he wrote on Telegram.

Last week, Russia captured the last major stronghold of Ukrainian resistance in Luhansk, the city of Lysychansk. Analysts predicted Moscow’s troops likely would take some time to rearm and regroup.

But “so far there has been no operational pause announced by the enemy. He is still attacking and shelling our lands with the same intensity as before,” Haidai said. He later said the Russian bombardment of Luhansk was suspended because Ukrainian forces had destroyed ammunition depots and barracks used by the Russians.

Ukraine’s deputy prime minister, Iryna Vereshchuk, appealed to residents of Russian-held territories in the south to evacuate quickly so the occupying forces could not use them as human shields during a Ukrainian counteroffensive.

“You need to search for a way to leave, because our armed forces are coming to de-occupy,” she said. “There will be a massive fight.”

It was not clear how civilians were expected to safely leave Russian-controlled areas as missile strikes and artillery shelling continue in surrounding areas, whether they would be allowed to depart or even hear the government’s appeal.

Meanwhile, five people were killed and eight more wounded in Russian shelling Friday of Siversk and Semyhirya in the Donetsk region, its governor, Pavlo Kyrylenko, wrote Saturday on Telegram.

In the city of Sloviansk, named as a likely next target of Russia’s offensive, rescuers pulled a 40-year-old man from the rubble of a building destroyed Saturday by shelling. Kyrylenko said multiple people were under the debris.

Russian missiles also killed two people and wounded three others Saturday in the southern city of Kryvyi Rih, according to regional authorities.

“They deliberately targeted residential areas,” Valentyn Reznichenko, governor of the eastern Dnipropetrovsk region, said on Telegram. Kryvyi Rih’s mayor, Oleksandr Vilkul, asserted on Facebook that cluster munitions had been used and urged residents not to approach unfamiliar objects in the streets. More explosions were reported Saturday evening.

Kryvyi Rih is the hometown of Ukrainian President Volodymyr Zelenskyy.

In northeast Ukraine, a Russian rocket strike on Saturday hit the center of Ukraine’s second-largest city, Kharkiv, injuring six people, including a 12-year-old girl, authorities said.

“One of the missiles hit a two-story building, which led to its destruction. Neighboring houses were damaged,” the Kharkiv regional prosecutor’s office said.

The city has been targeted throughout the war, including several times in the past week.

Mykolayiv Mayor Oleksandr Senkevych reported on Telegram that six Russian missiles were fired at his city in southern Ukraine near the Black Sea, but caused no casualties.

Russian defense officials claimed Saturday that their forces destroyed a hangar housing U.S. howitzers in the Donetsk region, near the town of Chasiv Yar. There was no immediate response from Ukraine.

In other developments:

Zelenskyy dismissed Ukraine’s ambassador to Germany, Andriy Melnyk. He was persistently critical of Germany’s perceived slowness to provide heavy weapons. He also faced criticism for an interview in which he defended Stepan Bandera, a controversial World War II-era Ukrainian nationalist. Melnyk had served in the post since 2015. Zelenskyy dismissed several other ambassadors as well.

The British Defense Ministry said Russian forces in Ukraine were now being armed with “obsolete or inappropriate equipment,” including MT-LB armored vehicles taken out of long-term storage that do not provide the same protection as modern tanks.