(CNN) – When a series of explosions rocked a Russian air base in Crimea on Tuesday, sending Russian vacationers fleeing from nearby beaches, it was clearly an embarrassment for Moscow. Western officials and analysts have since offered competing explanations about the cause.
The Russian Defense Ministry said the explosions — which sent enormous columns of smoke over the surrounding area — were caused by the accidental detonation of ammunition, and that no aircraft had been damaged.
But satellite imagery reviewed by CNN and other media, as well as Western security agencies, show at least eight aircraft were damaged, as was infrastructure at the air base at Novofedorivka, on Crimea’s west coast. One person was killed and 14 injured, the Crimean health ministry said.
The Ukrainian Ministry of Defense noted the explosions in messages on social media but offered no explanation for them.
On Friday, the UK Ministry of Defence said: “The original cause of the blasts is unclear, but the large mushroom clouds visible in eyewitness video were almost certainly from the detonation of up to four uncovered munition storage areas.
“At least five Su-24 FENCER fighter-bombers and three Su-30 FLANKER H multi-role jets were almost certainly destroyed or seriously damaged in the blasts.”
Western military analysts assessed the air base’s apron was badly damaged and that buildings away from the apron were also damaged.
Crisis and risk analysts at the Cavell Group noted commentary about “crater sizes, a possible Ukrainian SF [special forces] attack, partisans and more, but most indications are Ukrainian modified ballistic cruise missiles were used.”
In any event, the Cavell Group said, the “Saki attack was audacious and highly effective in both damaging Russian reinforcements and striking a significant psychological blow to morale amongst the Russian military and civilians.”
Nearby Crimean beaches were crowded with holidaymakers. There was a subsequent exodus from Crimea of hundreds of civilian vehicles across the Kerch Strait bridge, causing miles-long tailbacks. Russia illegally annexed the Ukrainian peninsula in 2014.
The Institute for the Study of War (ISW), a Washington-based analytical group, agrees that the jury is still out on what caused the explosions, absent any official statement from the Ukrainians.
“ISW still cannot independently assess what caused the explosions at the airfield — satellite imagery depicts multiple craters and scorch marks, but such damage could have been caused by many things — special forces, partisans or missiles, on-site or from a distance,” ISW said in its update Wednesday.
It also noted that Russian accounts of the incident have been confused.
“Mixed stories in Russian media and among Russian milbloggers indicate that either officials within the Russian Ministry of Defense have competing theories regarding the attack and are sharing them with the media, or that the Kremlin has failed to coordinate its information operation,” ISW said.
A prominent military blogger in Russia, Yuri Podolyak, said Thursday that “judging by the [satellite] images from the Americans, it was just an act of sabotage, a terrorist attack.”
He was also critical of the safety precautions at the air base.
“Storage and ammunition depots were hit. By the way, they were only a couple of hundred meters from the residential area, and they were completely open, which already brings us to the question of what the command of this military unit was thinking about,” Podolyak said. His Telegram channel has 2.2 million subscribers.
“I think it was a combination of sabotage with negligence. When the warehouses were already hit, there was an explosion of fuel and ammunition. I have questions for the command of this air regiment: how is it possible to store ammunition like this?”
Another military blogger in Russia who goes by the name Rybar, with more than 600,000 subscribers, suggested the explosion was likely not caused by a missile strike.
Rybar noted that “none of the huge number of vacationers and residents of Novofedorivka observed the arrival of rockets. Numerous videos from the scene also do not show anything resembling an incoming munition.”
CNN’s review of available imagery did not detect any incoming rockets or missiles, but the base is very close to the Black Sea.
Rybar speculated that a helicopter with a small bomb could have detonated fuel and ammunition, setting off a chain of explosions across the airfield. “The main source of ignition and subsequent detonations was located approximately in the area of one of the aircraft stands,” he said.
While there is no evidence to support this scenario, Ukrainian helicopters have flown deep behind enemy lines before — notably in missions to the besieged Azovstal plant in Mariupol.
Rybar also suggested negligence as a possibiilty. “Similar cases have already occurred in Syria, when the carelessness of local military personnel led to the loss of aircraft.”
Whatever caused the explosions, they could have significant implications for the overall conflict, especially if the attack were to have been carried out with any new long-range weapon system that Ukraine has developed.
The UK Ministry of Defence says that the loss of eight combat jets represents a minor proportion of the overall fleet of aircraft Russia has available to support the war.
But it noted that Saki is the main base for supporting the Russian navy in the Black Sea. “The fleet’s naval aviation capability is now significantly degraded. The incident will likely prompt the Russian military to revise its threat perception,” it said.
It may also cause a re-evaluation of the threat to Crimea which “has probably been seen as a secure rear-area,” the ministry said.
And the Cavell Group said: “Many Russian strategic defences, infrastructure and military sites could be targeted within this range, some crucial to Russia’s invasion.”
Ukrainian commanders have already said that targets in Crimea are on their list.
In an interview earlier this week, Ukrainian Major General Dmytro Marchenko was asked whether targeting the only road bridge into Crimea from Russia across the Kerch Strait would be part of the Ukrainian military’s plan.
“Yes, this is a necessary measure in order to deprive them of the opportunity to provide reserves and reinforce their troops from Russian territory,” Marchenko replied.
