Ukrainian forces were making a major effort to punch through Russian defensive lines in southeast Ukraine for a second day, a Moscow-installed official said Monday, as Russia’s Defense Ministry declared that it had foiled an assault in an illegally annexed region of the invaded country.

Kyiv authorities suggested the attack reports were a Russian misinformation ruse as the Ukrainian military prepares for a widely anticipated counteroffensive after more than 15 months of war.

Vladimir Rogov, an official in the Russia-backed administration of Ukraine’s partly occupied Zaporizhzhia province, said that fighting resumed on its border with the eastern Donetsk region on Monday after Russian defenses beat back a Ukrainian advance the previous day.

“The enemy threw an even bigger force into the attack than yesterday (Sunday),” and the new attempt to break through the front line was “more large-scale and organized,” Rogov said, adding: “A battle is underway.”

Rogov interpreted the Ukrainian military movements as part of an effort to reach the Sea of Azov coast and sever the land corridor to the Crimean Peninsula, which Moscow annexed in 2014.

Analysts have long viewed that strategy as likely because it would cut the Russian forces in two and severely strain supplies to Crimea, which has served as a key Russian military hub in the war that started on Feb. 24, 2022.

Rogov’s comments came after Moscow also claimed to have thwarted large Ukrainian attacks in Donetsk province, near its border with the Zaporizhzhia region.

Zaporizhzhia and Donetsk are two of the four provinces that President Vladimir Putin claimed as Russian territory last fall and which Moscow partially controls.

Russia’s Defense Ministry said that it had pushed back a “large-scale” assault Sunday at five places in Donetsk province. The announcement couldn’t be independently verified, and Ukrainian officials didn’t confirm any assaults.

Ukraine often waits until the completion of its military operations to confirm its actions, imposing news blackouts in the interim. However, the unconfirmed reports fueled speculation that a major Ukrainian ground operation could be underway as part of the anticipated counteroffensive.

A video published by the Ukrainian Defense Ministry showed soldiers putting a finger to their lips in a sign to keep quiet. “Plans love silence,” it said on the screen. “There will be no announcement of the start.”

Russian Defense Ministry spokesman Igor Konashenkov claimed in an unusual overnight video that 250 Ukrainian personnel were killed in the fighting in Donetsk province, and 16 Ukrainian tanks, three infantry fighting vehicles and 21 armored combat vehicles were destroyed.

“The enemy’s goal was to break through our defenses in the most vulnerable, in its opinion, sector of the front,” Konashenkov said. “The enemy did not achieve its tasks. It had no success.”

The Russian ministry said the alleged attack started Sunday morning but waited until early Monday to announce it.

In response, the Center for Strategic Communications of the Armed Forces of Ukraine said on Telegram that Russian forces were “stepping up their information and psychological operations.”

“In order to demoralize Ukrainians and mislead the community (including their own population), Russian propagandists will spread false information about the counteroffensive, its directions and the losses of the Ukrainian army. Even if there is no counteroffensive,” a statement on Telegram read.

Ukrainian officials have said for months that a spring campaign with advanced weapons supplied by Western allies to reclaim territory seized by Russia during the war was planned, but they have kept quiet about when and where it might start, or whether it had already launched.

Recent military activity, including drone attacks on Moscow, cross-border raids into Russia and sabotage and drone attacks on infrastructure behind Russian lines, has unnerved Russians. Analysts say those actions may represent the start of the counteroffensive.

In other disruption, TV and radio broadcasts in several regions of Russia were hacked Monday, according to Kremlin spokesman Dmitry Peskov. A fake broadcast featured a voice impersonating Putin and stated that Ukrainian forces had invaded the Belgorod, Bryansk and Kursk regions of Russia.

The impersonator announced that martial law was declared in those regions, where people were urged to evacuate, and all Russians eligible for military duty were being mobilized, Peskov said in remarks carried by Russian news agencies.

The Russian military on Monday said that it repelled the latest Ukrainian incursion into the Belgorod region, on the border in Ukraine. Russians who purport to be fighting alongside Ukrainian forces said they attacked on Sunday. They were driven back by airstrikes and artillery fire, according to the Russian Defense Ministry.

Michael Clark, the former head of the Royal United Services Institute think tank, said that the “increased tempo” of activity in recent weeks probably marked the start of the counteroffensive and that June was likely to see the start of Ukraine’s ground operation.

“There’s something going on,” he told the BBC.

At least two factors have been at play in the timing: better ground conditions for the movement of troops and equipment after the winter, and the deployment of more advanced Western weapons and training of Ukrainian troops to use them.

Ukraine’s Western allies have sent the country more than 65 billion euros ($70 billion) in military aid to help its defense. Driving out the Kremlin’s forces is a daunting challenge for Kyiv’s planners. Russia has built extensive defensive lines, including trenches, minefields and anti-tank obstacles.

Ukraine could launch simultaneous pushes in different areas of the front line that stretches for around 1,100 kilometers (nearly 700 miles), analysts say.

The Russian Defense Ministry spokesman said Ukraine used six mechanized and two tank battalions in the Donetsk attacks. The ministry released a video that it said showed the destruction of some of the equipment in a field.

In a rare specific mention of the presence of Russia’s top military leaders in battlefield operations, Konashenkov said the chief of the general staff of the Russian armed forces, Gen. Valery Gerasimov, “was at one of the forward command posts.”

Announcing Gerasimov’s direct involvement could be a response to criticism by some Russian military bloggers and by Yevgeny Prigozhin, the head of Russian mercenary group Wagner, that Russia’s military brass hasn’t been visible enough at the front or taken sufficient control or responsibility for their country’s military operations in Ukraine.

(AP)