Ukraine launched a series of long-range drones against targets in Russia on Tuesday, according to Russian officials who reported at least two oil facilities had been struck during an attack across eight regions in Russia.

Soldiers that Kyiv officials claim are Russian volunteers fighting for Ukraine have reported to have crossed the border into Russia, as they have periodically done throughout the war. Russia claims it had fought back against attempted incursions, but it was not possible to verify the claims of either side, and any substantial reports of border fighting remain unclear.

Propaganda is a common war theme, and the alleged incursions reported are occasionally the subject of claims and counterclaims.

One Ukrainian drone is believed to have hit an oil refinery and exploded into flames in the Nizhny Novgorod region, according to regional governor Gleb Nikitin and reported by The Associated Press.

The Novgorod region is located about 775 kilometers (480 miles) from the Ukraine border.

A drone was also shot down in Moscow, said Sergei Sobyanin, the city's mayor. Despite blocking the hit and shooting down the drone well south of the city center, it was exceptionally close to Zhukovsky Airport. The airport is one of Moscow's four international airports.

Another drone hit an oil depot in Oryol, 116 kilometers (95 miles) from Ukraine.

The strikes are just another display of Ukraine's expanding capabilities in domestic drone technology and its forward approach in taking the war over to Russia, especially after Kremlin forces launched a full-scale invasion of Ukraine on Feb. 24, 2022.

Last year, Ukrainian President Volodymyr Zelensky mentioned Ukraine was developing a weapon of war that could target 700 kilometers (400 miles) away without openly referencing drones.

An increase in sea drones has been released into the Black Sea by Ukraine, where it claims to have sunk Russian warships.

Kyiv forces expect more military aid from Ukraine's Western allies but currently struggle against a more equipped Russian army that shows no signs of holding back.

However, Zelensky reveals that Russian advances have slowed down as the battlefield situation is much better now than where it was in previous months.

"We had some difficulties due to the lack of artillery shells, long-range weapons, sky blocking, and the high density of Russian drones," Zelenskyy said in an interview with France's BFM TV and Le Monde published late Monday on the Ukrainian presidential website.

Ukrainian fighters sought to cross into Tetkino, a town on the border of Russia's Kursk region, claims Governor Roman Starovoit.

"There was an attempt by a sabotage and reconnaissance group to break through. There was a shooting battle, but there was no breakthrough," he said in a video message on Telegram.

Four attacks in what the Russian Defense Ministry called Ukrainian sabotage were driven back into Tetkino.

The representative of Ukraine's intelligence agency, Andrii Yusov, told Ukrainska Pravda that the military groups are made up of Russian citizens.

"On the territory of the Russian Federation, they operate completely autonomously and independently," he said.