A woman passes with a bicycle as a local resident works to clean the debris from a damaged house after Russian shelling in Kramatorsk, Ukraine, Thursday. Andriy Andriyenko/Associated Press

KYIV, Ukraine — Russia said it began withdrawing troops from a strategic Ukrainian city Thursday, creating a potential turning point in the grinding war, while a Ukrainian official warned that Russian land mines could render Kherson a “city of death.”

Ukrainian officials acknowledged Moscow’s forces had no choice but to flee Kherson, yet they remained cautious, fearing an ambush. With Ukrainian officials tight-lipped with their assessments, reporters not present and spotty communications, it was difficult to know what was happening in the port city, where the residents who remained after tens of thousands fled were afraid to leave their homes.

A forced pullout from Kherson — the only provincial capital Moscow captured after invading Ukraine in February — would mark one of Russia’s worst war setbacks. Recapturing the city, whose pre-war population was 280,000, could provide Ukraine with a launching pad for supplies and troops to try to win back other lost territory in the south, including Crimea, which Moscow seized in 2014.

Ukrainian forces seem to be scoring more battlefield successes elsewhere in the Kherson region and closing in on the city. President Volodymyr Zelensky said Thursday night the pace has increased so much that residents “are now checking almost every hour where our units have reached and where else our national flag was raised.”

The armed forces commander-in-chief, Gen. Valeriy Zaluzhny, said Kyiv’s forces have advanced 22.7 miles and retaken 41 villages and towns since Oct. 1 in the province, which the Kremlin has illegally annexed. That included 12 settlements on Wednesday alone.

Ukrainian presidential adviser Mykhailo Podolyak said Russian troops laid mines throughout Kherson as they withdrew to turn it into a “city of death” and predicted they would shell it after relocating across the Dnieper River.

From these new positions, the Kremlin could try to escalate the 8 1/2-month war, which U.S. assessments showed may already have killed or wounded tens of thousands of civilians and hundreds of thousands of soldiers.

Arkadiy Dovzhenko, who fled Kherson in June, said his grandparents still living there told him Thursday that “the Russians were bringing a lot of equipment into the town and also mining every inch of it.”

Zelenskyy said Thursday night his forces were racing to remove land mines from 65,637 square miles nationwide and planned also to do so in Kherson. A spokeswoman for Ukraine’s southern military, Natalia Humeniuk, said on Ukrainian television that resistance forces working behind enemy lines “carefully collect information” about critical infrastructure threatened by mines.

A local resident works to clean the debris from a damaged house after Russian shelling in Kramatorsk, Ukraine, Thursday. Andriy Andriyenko/Associated Press

Russian Defense Minister Sergei Shoigu ordered a troop withdrawal from Kherson and nearby areas on Wednesday after his top general in Ukraine reported that a loss of supply routes during Ukraine’s southern counteroffensive made a defense “futile.”

Shoigu’s ministry reported Thursday a “maneuver of units of the Russian group” to the Dnieper River’s eastern bank, also known as its left bank.

On Thursday, Ukrainian officials appeared to soften the skepticism they had expressed over whether the Russians were really on the run or trying to trap Ukraine’s soldiers. “The enemy had no other choice but to resort to fleeing,” armed forces chief Zaluzhny said, because Kyiv’s army destroyed supply systems and disrupted Russia’s local military command.

Still, he said the Ukrainian military could not confirm a Russian withdrawal.

Alexander Khara, of the Kyiv-based, think tank Center for Defense Strategies, echoed those concerns, saying he remained fearful that Russian forces could destroy a dam upriver from Kherson and flood the city’s approaches. The former Ukrainian diplomat also warned of booby traps and other possible dangers.

“I would be surprised if the Russians had not set up something, some surprises for Ukraine,” Khara said.

Russian President Vladimir Putin, who just over a month ago celebrated the annexation of Kherson and three other Ukrainian regions and vowed to defend them by any means, has not commented on the withdrawal.

A resident said Kherson was deserted Thursday and that explosions could be heard from ​​​around Antonivskiy Bridge — a key Dnieper River crossing that Ukrainian forces have repeatedly bombarded.

“Life in the city seems to have stopped. Everyone has disappeared somewhere and no one knows what will happen next,” said Konstantin, a resident whose last name was withheld for security reasons.

A self-propelled artillery vehicle fires near Bakhmut, Donetsk region, Ukraine, Wednesday. LIBKOS via AP

He said Russian flags have disappeared from the city’s administrative buildings, and no signs remain of the Russian military personnel who earlier moved into the apartments of evacuated residents. Russian state news agency Tass reported that emergency services such as police officers and medical workers would leave along with the last Russian troops.

Halyna Lugova, head of the Ukrainian administration of Kherson city, told Ukrainian television Thursday that the Russian military was moving vehicles towards the Antonivskiy Bridge. Lugova, who is now based in Ukrainian-controlled territory, described conditions in the city as brutal.

Kherson remains without power, heating and internet service, gas stations in the city are closed, and there is no fuel, she said. The city also has run out of medications for cancer and diabetes patients. Ukrainian news reports said the Russians blew up the local television center, some of the cellphone towers and energy infrastructure.

Ukrainian officials have been cautious at other times in declaring victories against a Russian force that at least initially outgunned and outnumbered Ukraine’s armed forces.

Orysia Lutsevych, head of the Ukraine Forum at international affairs think-tank Chatham House, said the reticence explains “why, until Ukrainians are in the city, they don’t want to declare that they have it (in) control.”

British Prime Minister Rishi Sunak was similarly cautious. He spoke to Zelenskyy on Thursday, and his office said they agreed “it was right to continue to exercise caution until the Ukrainian flag was raised over the city.”

Army Gen. Mark Milley, chairman of the U.S. Joint Chiefs of Staff, said Wednesday he believed a retreat was underway, but that Russia had amassed as many as 30,000 troops in Kherson and that a full withdrawal could take several weeks.

One analyst noted that the Ukrainian army has destroyed bridges and roads as part of its counteroffensive, making a quick transfer of Russian troops across the Dnieper River impossible.

“The main question is whether the Ukrainians will give the Russians the opportunity to calmly withdraw, or fire at them during the crossing to the left bank,” Ukrainian military analyst Oleh Zhdanov said. “The personnel can be taken out on boats, but the equipment needs to be taken out only on barges and pontoons, and this is very easily shelled by the Ukrainian army.”

Putin’s allies rushed to defend the retreat as tough, but necessary. However, Pro-Kremlin political analyst Sergei Markov broke ranks and described the move as “Russia’s biggest geopolitical loss since the collapse of the Soviet Union” and warned that “political consequences of this huge loss will be really big.”

Karmanau reported from Tallinn, Estonia. Raf Casert contributed from Brussels. Jill Lawless contributed from London. Andrew Katell contributed from New York.