Russia reported a series of blasts in the south of the country and a fire at an ammunition depot on Wednesday, the latest in a spate incidents that a top Ukrainian official described as payback and "karma" for Moscow's invasion.
Without directly admitting that Ukraine was responsible, presidential adviser Mykhailo Podolyak said it was natural that Russian regions where fuel and weapons are stored were learning about "demilitarisation".
The use of that word was a pointed reference to Moscow's stated objective for the nine-week-old war in Ukraine, which it calls a special military operation to disarm and "denazify" its neighbour.
"If you (Russians) decide to massively attack another country, massively kill everyone there, massively crush peaceful people with tanks, and use warehouses in your regions to enable the killings, then sooner or later the debts will have to be repaid," Podolyak said.
The blasts on Wednesday followed a major fire this week at a Russian oil storage facility in the Bryansk region near the border.
Earlier this month, Russia accused Ukraine of attacking a fuel depot in Belgorod with helicopters, which a top Kyiv security official denied, and opening fire on several villages in the province.
The incidents have exposed Russian vulnerabilities in areas close to Ukraine that are vital to its military logistics chains.
In the latest incidents, Belgorod regional governor Vyacheslav Gladkov said a fire at an ammunition depot had been extinguished and no civilians have been injured.
Roman Starovoyt, the governor of Kursk, another province that borders Ukraine, said explosions had also been heard in Kursk city early on Wednesday and that they were most likely the sounds of air defence systems firing.
He later said that a Ukrainian unmanned aerial vehicle was intercepted in the sky over Kursk region, adding that there were no casualties or damage.
In Voronezh, the administrative centre of another southern province, TASS news agency cited an emergencies ministry official as saying that two blasts had been heard and the authorities were investigating.
Regional governor Alexander Gusev said in the morning that an air defence system had detected and destroyed a small reconnaissance drone.
Russia said it was sending investigators to Kursk and Voronezh regions to document what it calls "illegal actions by the Ukrainian army".
Ukraine's Podolyak said it was not possible to "sit out" the Russian invasion. "And therefore, the disarmament of the Belgorod and Voronezh killers' warehouses is an absolutely natural process. Karma is a cruel thing," he said.
