By Kevin Liffey for Reuters
One person has been killed when a Russian air base near seaside resorts in the annexed Crimean peninsula was rocked by a series of blasts that Moscow said were detonations of stored ammunition, not the result of any attack.
Local witnesses said they had heard at least 12 explosions around 3.20 pm local time (1220 GMT) from the Saky air base near Novofedorivka on the west coast of the peninsula, which Russia annexed from Ukraine in 2014 and used in February as one of the launchpads for its invasion of Ukraine.
Crimea, a holiday destination for many Russians, has so far been spared the intense bombardment and artillery combat that other areas of eastern and southern Ukraine have suffered since Russian forces entered the country.
Russia's defence ministry was adamant that the "detonation of several aviation ammunition stores" had caused an explosion, and said initially that no one had been harmed. It said there had been no attack and no aviation equipment had been damaged.
Russia's main news agencies quoted an unnamed ministry source as saying that "only a violation of fire safety requirements is considered as the main reason for the explosion of several ammunition stores at the Saky airfield".
"There are no signs, evidence or, even less, facts (to indicate) a deliberate impact on ammunition stores," the source was quoted as saying.
Crimea's health department said one civilian had been killed. It said another person had been admitted to hospital with moderate injuries and five had been treated for minor wounds.
Ukraine issued a statement in a heavily suggestive tone reminiscent of its response to unexplained blasts on Russian territory during the conflict.
"The Ministry of Defence of Ukraine cannot determine the cause of the fire, but once again draws attention to fire safety rules and the ban on smoking in uncertified places," it said.
"We can't rule out that the occupiers will 'accidentally' find some characteristic 'insignia', 'visiting card' or even 'DNA'."
Moscow could accuse Kyiv of crossing a red line if Ukraine were to acknowledge it had attacked territory that Russia sees as its own.
The Russian governor of Crimea, Sergei Aksyonov, said a five kilometre exclusion zone had been established around the air base.
The base is close to the seaside resorts of Novofedorivka and Saky, but the Russian tour operators' association said they did not appear to have been affected.
However, one local witness told Reuters there was an official roadblock on the main road out of Novofedorivka, which leads in the direction of the base.
Numerous videos taken from beaches were posted on social media, showing huge plumes of smoke in the distance.
Novofedorivka and Saky are around 50 km north of the port of Sevastopol, home of Russia's Black Sea Fleet, which Moscow leased from Kyiv for decades before seizing and annexing the entire peninsula from Ukraine in 2014, in a move not recognised by most other countries.
On 31 July, an official in Crimea accused Ukraine of injuring five people in a drone attack in Sevastopol. Kyiv did not comment.