Russian forces have ramped up attacks in eastern Ukraine in an attempt to gain ground near two key front line cities, Ukrainian military officials said Sunday.

Moscow’s troops have begun a push to regain territory near Bakhmut, the eastern mining city that was the site of the war’s bloodiest battle before falling into Russian hands in May, the head of Ukraine’s ground forces wrote on the Telegram messaging app.

Ukrainian troops had recaptured the heights over Bakhmut and made some advances west, north and south of the city since Kyiv launched its summer counteroffensive.

“Toward Bakhmut, the Russians have become more active and are trying to recapture previously lost positions. … Enemy attacks are being repelled,” Col. Gen. Oleksandr Syrskyi wrote in a Telegram update on Sunday afternoon.

A Russian Defense Ministry spokesman said Sunday that Russian forces over the previous day repelled five Ukrainian attacks near Klischiivka and Kurdyumivka, two small settlements lying south of Bakhmut. Lt. Gen. Igor Konashenkov made the claim at the latest of regular press briefings.

Ukraine’s long-awaited counteroffensive has so far resulted in only incremental gains and heavy losses, with Ukrainian troops struggling to punch through Russian lines in the south. Meanwhile, Moscow’s forces have attempted to press forward in the northeast, likely with a view to distract Kyiv and minimize the number of troops Ukraine is able to send to key southern and eastern battles.

Ukraine’s General Staff said that Russian troops were also continuing their weekslong push to encircle Avdiivka, a Ukrainian stronghold south of Bakhmut and a key target since the beginning of the war. It’s considered the gateway to parts of the eastern Donetsk region under Kyiv’s control. The General Staff said Russia’s air force was playing a key part in the latest assault.

Gen. Oleksandr Tarnavskyi, who leads Ukrainian troops fighting in and near Avdiivka, said Sunday that the attacking Russian forces were ramping up airstrikes, particularly those using guided bombs. He wrote on Telegram that Russian troops had launched 30 airstrikes and 712 artillery barrages at the city and surrounding areas over the previous day, and clashed almost 50 times with Ukrainian units.

Also on Sunday, Ukraine’s intelligence agency claimed responsibility for a powerful blast in the country’s occupied south the day before that they said killed “at least three” officers serving with Russia’s internal military force.

In an online statement, the Main Intelligence Directorate (GUR) of Ukraine’s Ministry of Defense called the explosion, which rocked the headquarters of the Russian occupation authorities in the city of Melitopol on Saturday, “an act of revenge (…) carried out by representatives of the local resistance movement.”

“At least three officers of the Russian (National) Guard were eliminated,” the statement said, referring to Russia’s internal military agency that reports directly to the Kremlin.

It added that the strike was carried out “during a meeting of the occupiers” attended by National Guard officers as well as operatives from Russia’s main security agency, the FSB.

Melitopol, a city in Ukraine’s Zaporizhzhia region that had a pre-war population of over 150,000, was captured by Russian troops just days into the war. It now lies well behind its southern front line, even as a Ukrainian counteroffensive continues to grind on in Zaporizhzhia.

Russian authorities did not immediately respond to the Ukrainian claims, which could not be independently verified. The announcement came just over a day after more than a dozen freight cars carrying cargo in Russia’s western Ryazan region were derailed by an improvised explosive device, according to Russian law enforcement.

Nineteen carriages traveling from the town of Rybnoye were thrown from the tracks and 15 were damaged, investigators wrote in a statement on social media. They said they would be opening a criminal investigation on terrorism charges.

A regional branch of Ukraine’s public broadcaster, Suspilne, on Saturday cited anonymous sources from Ukraine’s GUR as claiming that the intelligence agency was behind the blast. A spokesman for the GUR, Andriy Yusov, that same day refused to confirm or deny the agency’s involvement, but said that similar strikes within Russia “will continue.” Yusov made the remarks in an interview with the Ukrainian armed forces’ official news service, ArmyInform.

Russian officials have previously blamed pro-Ukrainian saboteurs for several attacks on the country’s railway system since Moscow invaded the country in February 2022, although no group has claimed responsibility for the damage.

In the southern Ukrainian city of Kherson, a 64-year-old man was killed when Russian shells slammed into his yard, Ukrainian regional Gov. Oleksandr Prokudin said. Prokudin added that the man’s wife was hospitalized with a skull injury, concussion and shrapnel wounds to her legs.

Prokudin said that Russian forces shelled Kherson and the surrounding region 62 times over the previous 24 hours, wounding four civilians and damaging one of the city’s libraries. The city has come under near-daily attacks since Ukraine recaptured it a year ago.

(AP)