A week after an apparent Ukrainian attack on a Russian military base in occupied Crimea, an arms store at another military facility has been hit by a series of explosions.
Russian officials said a fire triggered the blasts in the Dzhankoi area, before blaming “sabotage”.
A separate fire broke out at a power sub-station and a railway was damaged.
A string of blasts last week destroyed Russian warplanes at a Black Sea base on the Crimean coast.
Ukraine has never publicly admitted that attack – but presidential office adviser, Mykhailo Podolyak, described the latest incident as “demilitarisation in action”, indicating that the explosions were not accidental.
A Ukrainian air force command spokesman said the base was used by some of Russia’s military helicopters, but blamed the blasts on Russia failing to observe fire precautions.
Russia gave no indication of the kind of sabotage involved in Tuesday’s attack, but the FSB security service said Ukrainian saboteurs had also blown up six electricity pylons this month inside Russia itself.
The attacks in the Kurchatov area, about 100km (60 miles) from Ukraine’s north-east border, had affected the “technological process of functioning” of the Kursk nuclear plant, it added.
Russia’s defence ministry said Tuesday’s explosions in northern Crimea took place at a temporal ammunition storage site on a base near the village of Maiske, at about 06:15 Moscow time (03:15 GMT).
A Crimean Tatar leader, Refat Chubarov, called the explosions a “hit” that could be heard “far across the steppe”.
The defence ministry in Moscow said there had been no “serious” casualties, but Russian-appointed regional head, Sergei Aksyonov, visited the site and said 2,000 people had been moved from a nearby village and two people had been wounded.
“One man has a shrapnel wound and one was crushed by a wall. Their lives are not in danger, fortunately,” he said.
Crimea was seized from Ukraine and then annexed by Russia in early 2014. When Russian forces unleashed a new invasion in February, they used their bases on the peninsula to capture large swathes of southern Ukraine. -BBC