"There is reason to believe that Ukrainian special services were involved," a Russian Foreign Ministry spokesperson said.

Russia’s Federal Security Service accused the man of planting an explosive device in the car, but said that it was detonated from Ukraine.

Russian authorities on Saturday said they had detained a suspect — whom they accused of being an “an agent of the Ukrainian special services” — in the car explosion that killed a senior Russian military officer on Friday. The Federal Security Service named the suspect as Ignat Kuzin, Reuters reports.