Anti-Russian sentiment is growing in occupied areas throughout Ukraine and has resulted in the killing of a Russian-appointed official targeted in a car bomb this week, British intelligence said Wednesday.  

The Moscow-appointed mayor of Velykyi Burluk, a small town in northern Ukraine located in the Kharkiv region, was allegedly targeted and killed by Ukrainian saboteurs Monday.

Kharkiv, which shares a border with Russia, was one of the strategic launch points used during Russia’s second wave of its invasion earlier this year once Moscow had abandoned attempts to take Kyiv. 

Ukraine Russia war wreckage

KHARKIV, UKRAINE - JUNE 26, 2022 - A State Emergency Service employee partakes in the response effort to the shelling of a northern neighbourhood by Russian troops with a BM-30 Smerch multiple rocket launcher, Kharkiv, northeastern Ukraine.  (Photo credit should read Vyacheslav Madiyevskyy/ Ukrinform/Future Publishing via Getty Images)

BELARUS LAUNCHES MILITARY DRILLS ON BORDER WITH UKRAINE, TESTS TROOP READINESS

Russian forces pushed southeast through Kharkiv into the Luhansk region and have since occupied the eastern half of the region. 

"Anti-Russian sentiment in occupied Ukraine is leading to Russian and pro-Russian officials being targeted," U.K. officials said in Wednesday's Defense Intelligence update. "The targeting of officials is likely to escalate, exacerbating the already significant challenges facing the Russian occupiers and potentially increasing the pressure on already reduced military and security formations."

The car bomb came the same day that Russian President Vladimir Putin announced a program that would fast-track Russian citizenship for Ukrainians. 

Residents of Donetsk and Luhansk were able to apply for Russian passports beginning in 2019. Roughly 18 percent of the population, an area known to house Russian sympathizers in the lead-up to the war, received passports from Moscow. 

Checkpoint near Kharkiv, Ukraine

Russian forces search a vehicle at a checkpoint near Kharkiv, Ukraine. (Russian Ministry of Defense)

RUSSIAN TROOPS' LACK OF REST IS ONE OF THE 'MOST DAMAGING' ISSUES FACING PUTIN'S ARMY IN UKRAINE, UK SAYS

Russia expanded the program to residents in the southern Zaporizhzhia and the Kherson regions, but it is unclear how many residents in these fiercely contested areas have voluntarily applied for Russian passports. 

Reports have surfaced since the beginning of the invasion that Russian troops have forcibly confiscated Ukrainian passports and identification cards.

"Russia continues to seek to undermine the legitimacy of the Ukrainian state and consolidate its own governance and administrative control over occupied parts of Ukraine," a U.K. defense officials said in response to the program.

Burned-out vehicles Ukraine

KHARKIV, UKRAINE - JUNE 26: Damaged cars are seen after shelling as the Russian-Ukraine war continues in Nemyshlyanskyi district of Kharkiv Oblast, Ukraine on June 26, 2022.  (Photo by Metin Aktas/Anadolu Agency via Getty Images)

CLICK HERE TO GET THE FOX NEWS APP

Putin declared victory over the Luhansk region last week and British intelligence warned Wednesday that Russian forces will now hone their efforts on taking small towns like Siversk and Dolyna.

Officials said this is part of Russia’s strategy as they push west across the Donbas from Luhansk towards cities in the region like Slovyansk and Kramatorsk. 

Ukraine has said it is planning a massive counter-offensive that involves up to 1 million servicemen. 

The Associated Press contributed to this report.