Ukrainian forces on Wednesday launched assaults along three major axes on the front lines, strengthening claims the counter-offensive is under way.
Kyiv said its forces had clawed back territory from Russia in an attack on the flanks of the eastern city of Bakhmut.
Meanwhile, Russian sources claimed Ukraine launched a major new offensive in the southern Zaporizhzhia region, armed with tanks and multi-launch rocket systems.
Probing attacks were reported by analysts in the Luhansk region of the Donbas, as infra-red satellites also picked up an increase in fires in the Kherson area.
The apparent pushes came a day after Ukraine accused Russia of destroying the Soviet-era Kakhovka dam, which unleashed a torrent of water that displaced tens of thousands of people and potentially hindered Kyiv’s plans for its counter-offensive.
Ukraine has a strict communications blackout surrounding counter-offensive activities.
“When we start the counter-offensive everyone will know about it, they will see it,” said Oleksiy Danilov, secretary of Ukraine’s National Security and Defence Council, dismissing reports of advances.
“Over the past day, we have advanced from 200 to 1,100 metres in various sections of the Bakhmut direction,” Hanna Maliar, Ukraine’s deputy defence minister, said.
“In the direction of Bakhmut, our troops switched from defence to offensive,” she added.
At the same time increased activity was reported across the entire stretch of the front lines dividing Ukraine from its Russian occupiers.
Russian military bloggers, some with close ties to the Kremlin, said advancing Ukrainian forces used artillery and armoured fighting vehicles in a new push towards Tokmak in the Zaporizhzhia region.
“Judging by the actions of the enemy, one should expect another attempt to attack this night or in the morning,” the War Gonzo blog wrote on Wednesday on Telegram
A short video shared alongside the post appeared to show clouds of white smoke rising above the horizon after strikes from a Ukrainian grad rocket launcher.
Analysts have long-predicted that Ukraine’s spring-summer counter-offensive could attempt to push south in order to sever the land bridge created by Moscow between Russia and occupied Crimea.
Ukrainian military reports of gains around Bakhmut were the first since senior officials earlier this week denied the start of the next phase of the conflict.
Colonel General Oleksandr Syrskyi, commander of Ukraine’s ground forces, also said Kyiv’s forces continued to advance along the flanks in Bakhmut as its Russian occupiers reportedly lost ground.
“Our defence forces continue to advance along the flanks, while the enemy is losing positions in Bakhmut,” he said.
The offensive push was largely carried out by members of Ukraine’s 3rd Separate Assault Brigade, which is part of the now-renowned Azov Brigade of fighters.
Footage of their exploits shared on social media appeared to show close-quarters fighting as Ukrainian forces swooped on foxholes left abandoned by the Russians.
Secure the high grounds
Kyiv’s men have been seeking to secure the high grounds to the north and south of Bakhmut, which Moscow claimed to have completely captured in May after almost a year of bloody combat, in what could become a double envelopment of the city.
Military analysts highlighted a Ukrainian push around the northern edge of Bakhmut and the nearby town of Soledar, as well as south-west of the salt-mining city.
In a television broadcast, Ms Maliar on Wednesday said Russia lacked forces in Bakhmut and was bringing in troops from other positions.
She said mercenaries from the Russian Wagner Group had been moved to rear positions around the city, with more professional airborne assault units brought into the fight.
“They don’t have enough strength. We destroy a lot of enemy manpower now, and we see that they redeploy their reserves from the depths in order to hold the strong defence,” the deputy defence minister added.
But Moscow’s defence ministry insisted it had repelled the attacks mounted by Ukraine.
“The adversary did not achieve the goal of the offensive, wedging into our defence positions has not been permitted,” it said.
On Tuesday, Yevgeny Prigozhin, the leader of Russia’s Wagner mercenaries who led the efforts to capture Bakhmut, said Moscow would need at least 200,000 troops to stall the offensive aimed at the city.
In the same broadcast, the warlord said Ukraine had already “broken through” Russia’s line of defence in several areas.
Earlier this week, Ukraine launched simultaneous offensives along the front lines but denied it was the start of its offensive, with officials claiming the reports were Russian disinformation to distract from its failings around Bakhmut.
Residents forced to flee floods
An uptick in Russian artillery fire was reported as residents of the southern Kherson region were forced to flee the floods triggered by the Kakhovka dam’s collapse.
Another potential environmental disaster emerged after an ammonia pipeline in the Kharkiv region started to spew gas into the atmosphere.
Russian sources published video of what was claimed to be a puncture in the pipeline, which stretches more than 2,000 miles between Tolyatti in western Russia and Odesa in the south of Ukraine.
The poisonous gas spewed from the pipeline could have devastating consequences for the nearby population living on the front lines that separate Ukrainian forces and the Russian occupiers.
Earlier this week, Ukraine said the line was damaged after repeated Russian shelling in the area of the infrastructure.
In response, Russian forces claimed the strike had been carried out by a sabotage group belonging to Kyiv’s military.
The pipeline is crucial for Russia’s global exports of fertiliser and could play a huge role in the deal for continuation of Ukrainian grain exports from its Black Sea ports.