Russia appeared to suffer its biggest loss of aircraft in a single day since the Second World War as fresh analysis of the explosive strike at an air base in occupied Crimea contradicted Moscow’s claim that no jets had been destroyed.
A review of new satellite images revealed at least 10 Russian planes had been destroyed or seriously damaged by the series of explosions that rocked the Saky air base in Novofedorivka on Tuesday afternoon.
Military analysts predicted the full extent of the damage sustained by Russia’s air force was still yet to be discovered, with some suggesting Moscow could have lost as many as 20 jets in the attack.
"The satellite imagery presents clear indications that the full tally is higher," the War Zone website wrote.
The assault, experts said, would also sow further doubt and unrest among the Russian military over its abilities to withstand an anticipated Ukrainian counter-offensive in the south of the country.
Independent analysts at Oryx, a website that tracks destroyed equipment, assessed four SU-30SM fighter jets had been destroyed, as well as five SU-24M bombers and reconnaissance aircraft.
The machines cost tens of millions of pounds each, leaving Russia with an estimated £500 million blow in destroyed aircraft.
Oryx estimates Russia has lost at least 47 aircraft since invading Ukraine on Feb 24, with a fifth of recorded losses happening at the Novofedorivka base.
Two buildings, believed to contain ammunition for the jets, were also wiped out in the blasts, satellite imagery appeared to show.
Russia's defence ministry said the explosions at the airfield were caused by a "violation of fire safety requirements" near to the munitions, and insisted its jets were undamaged.
Ukraine on Thursday still had not taken responsibility for the attack despite unofficial claims its special forces carried out the daring raid on the Russian site.
But Kyiv continued to mock Russia for the devastation caused by unexplained blasts, suggesting more could follow.
“Unless they want an unpleasantly hot summer break, we advise our valued Russian guests not to visit Ukrainian Crimea," Ukraine's defence ministry wrote on Twitter.
“Because no amount of sunscreen will protect them from the hazardous effects of smoking in unauthorised areas.”
The ministry on Thursday unveiled a glitzy social media video, soundtracked by Bananarama’s Cruel Summer, in which it discourages Russian holidaymakers from holidaying in occupied Crimea following the blast.
In its daily assessment of the conflict in Ukraine, the Institute for the Study of War, a US-based think-tank, said Kyiv was deliberately playing on Russian confusion over the attack.
"Ukrainian officials are playing up the evident Russian confusion surrounding the attack to obfuscate Ukraine’s longer-range capabilities," ISW wrote.
Without official confirmation of the attack, experts were on Thursday still pondering how Ukrainian forces had carried out the assault some 125 miles behind enemy lines.
Analysis of the craters left at the scene showed signs of possible missile strikes, which could have been launched from an unmanned drone, or explosive charges planted at the airfield.
Oliver Alexander, a Danish military analyst, said videos of the blasts had not been consistent with a missile attack, adding: "Two of the large explosions happen simultaneously to the second. While this is not impossible to achieve with a missile strike, it is easier to achieve with explosive charges placed by a special operation force on the ground."
Regardless, the attack raised questions over Russia's ability to defend Crimea, which was illegally annexed by Moscow in 2014, and its air attack and defence capabilities.
"Russians could consider moving their aircraft to the southern parts of the peninsula, which would increase fuel consumption for their aircraft operating near front lines," military analysts Rochan Consulting said.
Several units of S-400 surface-to-air rocket systems in the area were left unactivated if the strike was carried out with a missile, its experts added.
The Saky airfield, Ukrainian officials, said was a key staging post of aerial attacks on Kyiv's positions in the southern towns of Kherson and Mykolaiv.
Meanwhile, several explosions were reported on Thursday to have rocked a military airbase in Belarus near the Ukrainian border understood to be used by Russia as one of the launchpads for the invasion.
The Belarusian defence ministry dismissed speculation of a Ukrainian attack, two days after unexplained explosions at the airfield in Crimea.
Another fire was reported at a Russian military base near Moscow, where conscripts were said to have been stationed.
"The epidemic of technical accidents at military airfields in Crimea and Belarus should be considered by the Russian military as a warning: forget about Ukraine, take off your uniforms and leave," Mikhailo Podolyak, an adviser to Volodymyr Zelensky, the Ukrainian president, tweeted.
In the wake of the apparent Crimea attack, Russia doubled its air strikes on Ukrainian targets including civilians, according to Oleksiy Hromov, the Ukrainian Brigadier General.
Zaporizhzhia, Europe's largest nuclear power plant, also came under fresh bombardment by Russian shelling according to Energoatom, Ukraine's atomic energy agency.