Witnesses reported at least 12 explosions at Moscow’s Novofedorivka facility near the Black Sea resort of Saki, with Ukraine’s air force saying nine Russian jets were destroyed on Tuesday.
The fireballs, which killed one person and wounded 13, sent tourists fleeing in panic as plumes of smoke towered over the nearby coastline. They smashed windows and caused other damage in some apartment buildings.
The attack is significant because the base is far behind the frontline. It dangles off southern Ukraine and is around 150 miles away from the closest Ukrainian position.
The peninsula, occupied by Moscow’s forces since 2014 and used in February as one of its launchpads for its invasion, has so far been spared from the fighting.
So who or what was behind the attack and why does it matter?
Who carried out attack, and was it long-range US weapons?
Ukrainian officials have stopped short of publicly claiming responsibility for the explosions.
Asked whether Ukraine was taking responsibility, presidential aide Mykhailo Podolyak told the Dozhd online television channel: “Of course not. What do we have to do with this?”
However, the Washington Post reported on Wednesday that Ukrainian special forces were behind the daring attack, according to a Kyiv official.
The question is then how the attack was carried out as the resort is out of the range of the missiles supplied by the US for use in the Himars systems.
The Ukrainian military has successfully used those missiles, with a range of 50 miles, to target ammunition and fuel depots, strategic bridges and other key targets in Russia-occupied territories.
Himars could also fire longer-range rockets, with a range of up to about 185 miles, that Ukraine has asked for.
But US authorities have refrained from providing them thus far, fearing it could provoke Russia and widen the conflict.
The explosions in Saki raised speculation on social media that Ukraine might have finally got the weapons.
But a US official told the Post that Ukrainian forces appeared to have carried out the attack without using a weapon provided by Washington.
Ukrainian military analyst Oleh Zhdanov said the Ukrainian forces could have struck the Russian air base with a Ukrainian Neptune anti-ship missile that has a range of about 125 miles and could have been adapted for use against ground targets and fired from Ukrainian positions near Mykolaiv northwest of Crimea.
The Ukrainian military might also have used Western-supplied Harpoon anti-ship missiles that can also be used against ground targets and have a range of about 185 miles, he said.
“(Officially) Kyiv has kept mum about it, but unofficially the military acknowledges that it was a Ukrainian strike,” Zhdanov said.
Will Russia retaliate?
Russia denied any aircraft were damaged in the explosions – or that any attack took place – and Ukraine has poked fun at Russia’s explanation that munitions at the Saki air base caught fire and blew up.
On Wednesday, Russian authorities sought to downplay the explosions, saying all hotels and beaches were unaffected on the peninsula, which is a popular tourist destination for many Russians.
Officials in Moscow have long warned Ukraine that any attack on Crimea would trigger massive retaliation, including strikes on “decision-making centres” in Kyiv.
Why is it important?
In any case, the attack represents a dramatic escalation in the five-month long conflict, and the Russian response underscores the importance of the peninsula that Moscow annexed eight years ago.
If Ukrainian forces were responsible for the blasts, it would be the first known major attack on a Russian military site in Crimea.
A smaller explosion last month at the headquarters of Russia’s Black Sea Fleet in the Crimean port of Sevastopol was blamed on Ukrainian saboteurs using a makeshift drone.
In his nightly video address several hours after the blasts, Ukrainian president Volodymyr Zelenskyy did not specifically mention the blasts but vowed to retake the peninsula, saying “this Russian war against Ukraine and against all of free Europe began with Crimea and must end with Crimea — its liberation”.