A satellite view shows a smoldering building, in Soledar
A satellite view shows a smoldering building, in Soledar, Ukraine, January 3, 2023. Satellite image 2023 Maxar Technologies./Handout via REUTERS Reuters

Moscow named a new commander for its invasion of Ukraine while Russian private military firm Wagner Group said its capture of the salt mining town Soledar in eastern Ukraine was complete.

Russian Defence Minister Sergei Shoigu on Wednesday appointed Chief of the General Staff Valery Gerasimov as overall commander for what Moscow calls its "special military operation" in Ukraine, now in its 11th month.

The change effectively demoted General Sergei Surovikin, who was appointed only in October to lead the invasion and oversaw heavy attacks on Ukraine's energy infrastructure.

Meanwhile, Yevgeny Prigozhin, head of Wagner and a close ally of Russian President Vladimir Putin, said his forces had captured all of Soledar and killed about 500 Ukrainian soldiers after heavy fighting.

"I want to confirm the complete liberation and cleansing of the territory of Soledar," Prigozhin said in a statement.

"The whole city is littered with the corpses of Ukrainian soldiers," said Prigozhin.

U.S. Defence Secretary Lloyd Austin told reporters on Wednesday that he could not corroborate reports that Soledar was in Russian hands.

Reuters was unable to independently verify the situation in Soledar.

Ukrainian President Volodymyr Zelenskiy mocked previous Wagner claims to have seized part of Soledar but made no immediate comment on the latest assertions.

"The terrorist state and its propagandists are trying to pretend that part of our town of Soledar ... is some sort of a Russian possession," Zelenskiy said in a video address. "But fighting continues."

In a statement on Facebook, the Ukrainian military general staff said Russian forces were suffering heavy losses as they tried to take Soledar and sever Ukrainian supply lines.

Russia has struggled to cement control over the town, which would be Russia's most substantial gain since August after a series of retreats before Ukrainian counter-offensives in the east and south.

A Russian Defence Ministry statement said the command reshuffle was meant to improve contacts between military branches and the effectiveness of the command structure.

One prominent military blogger who posts on the Telegram messaging app under the name of Rybar said Surovikin was being made the fall guy for recent Russian military debacles. Those included a Ukrainian attack on a Russian barracks that killed at least 89 Russian soldiers over New Year's.

Surovikin was ordered to head the campaign after Ukrainian offensives turned the tide of the war and drew attention to poor training, equipment and morale among Russian forces.

If pro-Russian forces succeed in taking Soledar, it would be a stepping stone in Moscow's thrust to capture Ukraine's eastern Donbas industrial region. The town would be a base to attack the nearby city of Bakhmut, which has held out for months and is a supply line hub in eastern Ukraine.

Before Wagner's latest statement, the Kremlin stopped short of claiming victory and acknowledged heavy casualties.

"Let's not rush, let's wait for official statements. There is a positive dynamic in progress," Kremlin spokesman Dmitry Peskov said.

A Reuters photographer who reached the outskirts of Soledar in recent days said many residents had fled the town in perishing cold. Smoke could be seen rising over the town and the incoming artillery fire was relentless, she said.

MISSING BRITONS

Earlier, Russian state news agency RIA said Wagner had taken over Soledar's salt mines and a photograph on the militia's Telegram channel appeared to show Prigozhin and his fighters inside a mine.

Wagner separately said its forces found the body of one of two British voluntary aid workers reported missing in eastern Ukraine. It did not give the name of the dead man. A photo appeared to show passports bearing the names of Andrew Bagshaw and Christopher Parry, the two missing workers.

Russia sent tens of thousands of troops into Ukraine on Feb. 24, saying Kyiv's close ties with the West and ambitions to join NATO threatened its security. Kyiv and its allies accuse Moscow of an unprovoked war to seize territory in a neighbour it once dominated within the former Soviet Union.

A satellite view shows a destroyed school and buildings, in south Soledar
A satellite view shows a destroyed school and buildings in south Soledar, Ukraine, January 10, 2023. Satellite image 2023 Maxar Technologies./Handout via REUTERS Reuters
People in military uniform, claimed to be soldiers of Russian mercenary group Wagner pose for a picture believed to be in a salt mine in Soledar
People in military uniform, claimed to be soldiers of Russian mercenary group Wagner and its head Yevgeny Prigozhin, pose for a picture believed to be in a salt mine in Soledar in the Donetsk region, Ukraine, in this handout picture released January 10, 2023. Reuters
A satellite view shows apartment buildings and homes, in Soledar
A satellite view shows apartment buildings and homes, in Soledar, Ukraine, August 1, 2022. Satellite image 2023 Maxar Technologies./Handout via REUTERS Reuters