(NewsNation) — Ukraine continues to deny involvement in the death of 29-year-old Daria Dugina, the daughter of an influential Russian political theorist often referred to as “Putin’s brain.”

Russia’s Federal Security Service (FSB), the main KGB successor agency, blamed Ukrainian spy agencies on Monday, saying the killing of Dugina was “prepared and perpetrated by the Ukrainian special services.”

Authorities said Dugina was killed in a car bombing on the outskirts of Moscow by an explosive planted in the SUV she was driving Saturday night.

The bloodshed raised suspicion that the intended target was Dugina’s father, Alexander Dugin, a nationalist philosopher and writer who called for escalating the war in Ukraine. Some even credit him with being the architect behind the plan to invade the country.

Russian media reports cited witnesses as saying the SUV belonged to Dugin and that he had decided at the last minute to travel in another vehicle following an event with his daughter.

With the war between Ukraine and Russia hitting the six-month mark later this week, the car bombing over the weekend brings a new wave of worry about a possible response from Moscow.

President Joe Biden has yet to make a direct statement on the matter. During an appearance on CNN on Sunday, Rep. Adam Schiff — also chairman of the House Intelligence Committee — added they had not yet been briefed on Dugina’s killing. 

The Associated Press contributed to this report.