A blast in Ukraine's Russian-held city of Lugansk killed the separatist administration's top prosecutor and his deputy on Friday, pro-Moscow authorities said, while other attacks were reported in the south.
This is the latest of a series of targeted attacks against pro-Russian officials in occupied areas.
"Today, Prosecutor General Sergei Gorenko and his deputy Ekaterina Steglenko died as a result of a terrorist act," the press service of the leader of self-proclaimed Lugansk People's Republic, Leonid Pasechnik, said on Telegram.
Pasechnik said the attack that targeted the prosecutor's office "showed that Kyiv's regime had crossed all possible limits."
Two other pro-Moscow officials were killed overnight in the southern port city of Berdyansk, the head of the Russian-installed administration in the Zaporizhzhia region Yevgeny Balitsky said on Telegram on Friday.
Oleg Boyko was the deputy head of the Russian-installed administration in Berdyansk, while his wife Lyudmyla headed the electoral commission preparing for the referendum on joining Russia, according to Balitsky.
Occupying authorities have been pressing ahead with a campaign to bring the occupied territories closer to Russia, discussing referendum plans and giving out Russian passports to local residents.
There were also reports of intensifying fire on the southern front of Kherson where the Ukrainian army has been claiming gains over the past few days.
Vladimir Rogov, a Moscow-installed official in the southern Zaporizhzhia region, accused the Ukrainian army of striking Kherson city's administrative building, leaving one dead and one injured.