A modern Su-57 combat jet has been damaged in an attack by Ukrainian forces inside Russian territory almost 600 kilometres from the frontline, Ukraine's HUR military intelligence directorate said on Sunday.
At least one aircraft had been damaged in the attack on the Aktubinsk airbase in Astrakhan, the statement said. The Sukhoi Su-57 is a stealth jet that has been in service with the Russian air force since 2020.
HUR published a satellite photo claiming to show the attack. A HUR spokesman said later that a second jet could also have been damaged in the attack, Ukrainian media reported.
On Saturday, the Russian Defence Ministry reported that three Ukrainian drones had been downed over Astrakhan. It has not responded to the latest statements from Kiev.
The ministry said on Sunday that three Ukrainian drones had been downed in the Belgorod region close to the border with Ukraine.
Doubts about this report were raised when photos and videos appeared on social media showing a large fire. Unconfirmed reports spoke of a strike on an ammunition dump.
The reports did not make clear whether only Ukrainian drones were used in the two attacks.
Several countries, including the United States and Germany, have recently eased restrictions on the use of their weapons on Russian territory where this is to protect the region around the north-eastern Ukrainian city of Kharkiv. Belgorod lies some 70 kilometres north of Kharkiv.