KYIV, Ukraine (AP) — Russian forces claimed some battlefield success Wednesday as Moscow’s invasion of Ukraine laboured to gain momentum almost a year after it began, while Ukraine said it needs another few months to stage its own offensive.

The Russian Defense Ministry said its troops broke through two Ukrainian defensive lines in the eastern Luhansk region and pushed back Ukrainian troops some three kilometres (two miles), forcing them to leave behind equipment and the bodies of those killed.

It was not possible to independently verify Moscow’s claim. Ukrainian officials made no immediate comment.

Russian artillery, drones and missiles have relentlessly pounded Ukrainian-held areas in the country’s east for months, indiscriminately hitting civilian targets and wreaking destruction, as the war largely slowed to a grinding stalemate in the winter. Moscow is hungry for some progress after months of setbacks.

Meanwhile, Ukrainian Defense Minister Oleksiy Reznikov said his country’s forces would need “a few months” to learn how to use new Western weapons before they can try and push the Russians out of Ukraine.

The Donetsk and Luhansk regions, which together make up the industrial Donbas region bordering Russia, continue to bear the brunt of Russia’s bombardments as Moscow reportedly moves more troops into the area.

In Luhansk, the number of Russian ground and air attacks is “growing every day,” Gov. Serhii Haidai said on Ukrainian TV.

“The Russians were able to transfer new forces for the offensive and now they are trying to overwhelm us with sheer human mass,” Haidai said.

Donetsk Governor Pavlo Kyrylenko said Wednesday that one town had come under “non-stop” fire from multiple rocket launchers for over three hours the previous day that damaged at least 12 residential buildings.

At least 12 civilians were wounded when Russian forces struck a five-story apartment block in the city of Pokrovsk, Kyrylenko said. Two others remained under the rubble.

Meanwhile, Kyiv’s military administration said that six apparent reconnaissance balloons were detected floating over the capital on Wednesday. Ukrainian air defence systems shot down “most of” them, an online statement read, adding that the balloons “could carry corner reflectors and certain reconnaissance equipment” and were designed to “identify and deplete” Ukraine’s air defences.

The statement promised more details about the objects following “a detailed study and analysis.”

With the one-year anniversary of Russia’s war approaching, followed by improved spring weather, Western officials and analysts say the fighting could be nearing a critical phase when both sides look to launch offensives.

The Kremlin is striving to secure eastern areas it illegally annexed in September — the Donetsk, Kherson, Luhansk and Zaporizhzhia regions — and where it claims its rule is welcomed. Pro-Moscow separatists have controlled part of Donetsk and neighbouring Luhansk province since 2014.