The General Staff of the Armed Forces of Ukraine said Russian forces carried out air and artillery strikes near Stariy Saltiv and Mospanove in the Kharkiv region, adding that the Russians were conducting an offensive near Lebyazhe and Bazaliyivka, where the fighting continues.

In Donetsk, Russian troops attempted to advance near Bohorodychne but had to retreat, the General Staff reported, adding that fighting continued near Mazanivka and Novodmytrivka.

Donetsk Governor Pavlo Kyrylenko said on August 17 that two civilians were killed and seven wounded in shelling by Russian forces in the last 24 hours in the region.

In Moscow, the Defense Ministry said a Russian ammunition storage unit in occupied Crimea exploded on August 16, wounding at least two people and prompting the evacuation of thousands of nearby residents.

The ministry blamed the blast on sabotage, in a rare admission that armed groups loyal to Ukraine are damaging military logistics and supply lines on territory it controls.

Ukrainian officials avoided publicly or directly claiming responsibility for the incidents, but some appeared to suggest that Kyiv was involved.

Crimea was captured and annexed by Russia in 2014 and is still internationally recognized as Ukrainian territory, but Moscow has threatened severe reprisals for any attacks on the peninsula.

After the blasts, President Volodymyr Zelenskiy, in his nightly address on August 16, called on Ukrainians living in the occupied territories to stay away from the military facilities of the Russian Army located in Crimea.

"Every day and every night we see new reports of explosions in the territory temporarily occupied by the invaders," Zelenskiy said, without admitting direct responsibility for the blasts. He said the explosions could have various causes, including incompetence.

"But they all mean the same thing -- the destruction of the occupiers' logistics, their ammunition, military and other equipment, and command posts saves the lives of our people," he said.

Britain's Ministry of Defense said in its daily intelligence report that while the cause of the blasts remains unclear, it is "highly likely" that the incidents are causing increasing concerns among Russian commanders about the apparent deterioration of the security situation in occupied Crimea, which functions as a rear base for the occupation of Ukraine.

Mykhaylo Podolyak, another top Zelenskiy aide, said in a post on Twitter that the latest blasts were a reminder that the "Crimea occupied by Russians is about warehouses, explosions, and a high risk of death for invaders and thieves."

"What is stolen does not bring prosperity," Podolyak later told Ukrainian television.

The incidents came roughly a week after a series of unexplained explosions tore through Russia’s Saky air base, in a western district of Crimea, destroying a number of Russian warplanes.

There's been no confirmation as to what caused those explosions, though satellite imagery showed extensive destruction at the base.

The Dzhankoy district is about 50 kilometers from the Russian-occupied region of Kherson in southern Ukraine.

With reporting by Crimea.Realities and AP