Semyon Skrepetsky, 44, was killed on Monday morning when an attacker approached him in a car park near Terebelska Street and fired several shots.
Attempts to resuscitate him failed.
Skrepetsky was known for satirical paintings mocking Russian President Vladimir Putin, Chechen leader Ramzan Kadyrov and other Russian officials.
He had recently been in Berlin, where he took part in events focused on the war in Ukraine and Russian opposition activity.
He had also reportedly warned publicly about Russian and Belarusian influence operations in the West.
Police set up roadblocks across the city following the shooting.
According to Belarusian opposition news outlet Nexta, a taxi driver believed to have transported those involved was detained near the Belarusian consulate.
Investigators, however, have not confirmed this, and no evidence of foreign intelligence involvement has been established at this stage.
Authorities are reviewing CCTV footage and interviewing witnesses.
Police have appealed for anyone in the area that morning with dashcam or mobile phone footage to come forward.
Nexta linked the killing to a broader pattern of attacks on opposition figures, reporting that Lithuanian police had recently disrupted a network of hired killers allegedly tied to Russian security services.
The outlet said it could not be ruled out that other such cells were operating in Europe.
(ał/gs)
Source: Nexta, IAR, rp.pl