KYIV, UKRAINE -- Ukraine on Sunday said its forces hit an ultra-modern Russian warplane stationed on an air base nearly 600 kilometres (370 miles) from the front lines, after its Western allies allowed Kyiv to use their weapons for limited strikes inside Russia.

Kyiv鈥檚 main military intelligence service shared satellite photos it said showed the aftermath of the attack. If confirmed, it would mark Ukraine's first known successful strike on a Su-57 fighter plane, a twin-engine stealth fighter lauded as Moscow's most advanced military aircraft.

In one photo, black soot marks and small craters can be seen dotting a concrete strip around the parked aircraft. According to the Main Intelligence Directorate of Ukraine鈥檚 Ministry of Defense, the strike took place on Saturday at the Akhtubinsk base in southern Russia, some 589 kilometres (366 miles) from the front line.

It wasn鈥檛 immediately clear what weapons were used, but the airfield鈥檚 distance from Ukraine suggests that it was likely hit by drones.

The strike comes after the United States and Germany recently authorized Ukraine to hit some targets on Russian soil with the long-range weapons they are supplying to Kyiv. Ukraine has already used U.S. weapons to strike inside Russia under newly approved guidance from U.S. President Joe Biden that allows American arms to be used for the limited purpose of defending Kharkiv, Ukraine鈥檚 second-largest city.

The Ukrainian agency said that the plane, which is capable of carrying stealth missiles across hundreds of kilometres (miles), was among 鈥渁 countable few鈥 of its type in Moscow's arsenal. According to reports by Russian agencies, Moscow's armed forces obtained 鈥渕ore than 10鈥 new Su-57s last year, while 76 are set to be produced by 2028.

Moscow did not immediately comment on the reports. Russia's Defense Ministry on Saturday claimed its forces downed three Ukrainian drones in the Astrakhan region, home to the Akhtubinsk airstrip.

Since Moscow's full-scale invasion more than two years ago, Kyiv has ramped up domestic drone production and used the drones to strike deep inside Russia, including a gas terminal near St. Petersburg that lies over 1,000 kilometres (620 miles) north of the Ukrainian border.

Elsewhere, Ukrainian forces kept up drone attacks on Russia's southern border regions, according to local Russian officials.

Three drones hit Belgorod province late on Saturday, damaging a power line and blowing out windows but causing no casualties, said Gov. Vyacheslav Gladkov. The Russian Defense Ministry said another drone was shot down over the nearby Bryansk region.

Across Ukraine鈥檚 front-line provinces, Russian shelling killed at least three civilians and wounded at least nine others on Saturday and overnight, according to reports by regional officials. A man died and two women suffered wounds in the village of Khotimla in Ukraine's northeastern Kharkiv region, where shelling damaged the local school, a council building and a shop, Gov. Oleh Syniehubov said.

Heavy battles continue in the area as Ukrainian troops try to beat back Russia's invading forces after a weekslong push by Moscow that sparked fears for Kharkiv and a wave of civilian evacuations.