A car bomb killed Russian Lt. Gen. Fanil Sarvarov on Monday, marking the third high-ranking military assassination in just over a year, with investigators suggesting Ukraine may be behind the attack.

Sarvarov, 56, led the Operational Training Directorate of Russia’s General Staff and had fought in Chechnya and Syria.

Previous killings include Lt. Gen. Igor Kirillov, killed by a bomb on an electric scooter, and Lt. Gen. Yaroslav Moskalik, killed by a car explosive; Ukraine claimed responsibility for some of these operations.

Analysts say Ukraine uses targeted strikes and surprise attacks, including cross-border raids and drone strikes on Russian forces, to offset its smaller military size, the AP has reported.

Meanwhile, Russia has been accused of conducting sabotage operations across Europe to undermine support for Ukraine, which Moscow denies.