A Ukrainian strike on a bakery in the occupied eastern Ukrainian city of Lysychansk over the weekend killed three officials, Russian-installed representatives said Monday.
The Kremlin has blasted the attack that killed at least 28 people as a "monstrous terrorist act."
On Monday, authorities in the Russian-controlled Luhansk region said a local government minister and two deputies were among those killed.
"During the brutal shelling of the bakery in Lysychansk, the emergency situations minister of the Luhansk People's Republic, Colonel Alexey Poteleshchenko, was killed," the Moscow-appointed head of the region Leonid Pasechnik said in a post on the Telegram messaging app.
Luhansk is one of four Ukrainian regions that Moscow claims to have annexed since invading the country nearly two years ago.
Poteleshchenko fought in militia units for pro-Russian separatists against Ukraine before being appointed to the government post, Pasechnik said.
Two municipal deputies were also killed in the attack, Mayor Eduard Sakhnenko said in a post on social media.
Kyiv and Moscow have intensified attacks against each other in recent months, though the front line has barely moved.
The Kremlin said the latest incident justified its ongoing war against Ukraine.
"Continued strikes on civilian infrastructure, in this case the bakery, are monstrous terrorist acts. The number of victims speaks to the monstrousness of this terrorist act," Kremlin spokesman Dmitry Peskov said.
"To stop more of them, the special military operation is continuing," Peskov said, using Moscow's preferred term for the invasion of Ukraine.
Kremlin-backed officials in occupied Ukraine said 18 men, nine women and one child died when Ukrainian forces struck the building on Saturday.
