Editor's note: The article was updated with new information from the source that Su-27, not Su-24 aircraft, were based at the Morozovsk airbase.
An overnight attack against the Russian Morozovsk airbase on April 5 was carried out by the Security Service of Ukraine (SBU) in cooperation with Ukraine's military, sources familiar with the matter told the Kyiv Independent.
Su-34 fighter-bombers and Su-27 fighters were based at the airfield, the source said. Russia uses these aircraft to drop aerial bombs on Ukrainian military positions and Ukrainian front-line cities, according to the source.
Both Su-34 and Su-27 planes are estimated to cost over $35 million a piece.
At least six military aircraft were destroyed, and another eight were damaged, according to the source. Furthermore, about 20 Russian soldiers were reportedly killed or wounded.
The Kyiv Independent could not independently verify the information.
"This is an important special operation that will significantly reduce the combat potential of the (Russian forces)," the source commented.
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Earlier on April 5, Russia reported a massive Ukrainian drone attack against Russian regions, claiming to down 53 drones.
Russia's Defense Ministry claimed that the majority of the drones – 44 – were shot down over Rostov Oblast, where the Morozovsk airbase is located. Earlier, claims appeared on Telegram channels claiming that explosions were heard near the airbase.
Six more drones were allegedly downed in Krasnodar Krai, and one each in Kursk, Saratov, and Belgorod oblasts, the Russian Defense Ministry claimed.
Telegram channels reported explosions also near the Engels and Yeysk airbases, which are located in the Saratov and Krasnodar regions, respectively, but this information was not confirmed by Russian officials or the Kyiv Independent's sources.
In March, Ukrainian media reported that Ukrainian drones attacked the Engels base, claiming that "targets were hit" without clarifying which ones. Citing satellite images, Radio Free Europe/Radio Liberty's Schemes project said that there were 11 Russian military aircraft at the Engels airbase at the time of the attack, including six Tu-95 and three Tu-160 bombers.
Read also: Russia reports massive Ukrainian drone strike amid claims of airbase attacks