Editor's note: This item has been updated to include additional information.
Drones reportedly hit Russia's Engels military airbase in Saratov Oblast overnight, and other drone strikes were reported in Belgorod Oblast, Russian authorities and Telegram channels said on March 20.
Sources from Ukraine's military intelligence told the media outlet NV that its operatives were responsible for the attack on the airbase. Andrii Cherniak, a spokesperson for the military intelligence, told the Kyiv Independent that he could neither confirm nor deny its involvement.
Radio Free Europe/Radio Liberty's (RFE/RL) Schemes project reported that sources from military intelligence had said that Ukrainian drones had been used in the attack, and claimed that "targets were hit" but did not clarify which ones. Citing satellite images, Schemes said that there were 11 Russian military aircraft at the airbase at the time of the attack, including six Tu-95 and three Tu-160 bombers.
In past weeks, Ukrainian forces have launched a series of drone strikes aimed at damaging Russia's oil industry. Ukraine has hit oil refineries in multiple regions deep inside the Russian territory. Russian authorities have also claimed other attacks inside Russian territory, particularly in areas close to the Ukrainian border.
The uptick in claimed drone and artillery strikes comes against the backdrop of ongoing fighting between pro-Kyiv Russian militia and the Russian military on Russian territory.
Saratov Oblast Governor Roman Busargin wrote on Telegram that the city of Engels, home to a Russian air force base, was targeted by a drone attack. He claimed that there were no injuries or damage.
The Astra Telegram channel, citing sources, claimed that three drones landed on the territory of the airbase but could not confirm if the drones had caused damage or casualties on the ground.
The channel also shared a video that appeared to depict stationary camera footage of the airbase, in which a loud explosion could be heard.
Russia's Defense Ministry separately said that four drones had been shot down over Saratov Oblast and one in Belgorod Oblast.
The claims could not be independently verified.
Engels airbase, located some 700 kilometers (434 miles) from the Ukrainian border, has been previously attacked since the beginning of the full-scale invasion.
Kyiv often does not comment on claimed attacks within Russian territory.
Chris York
