Earlier reports said that the victim of the attack was Ruslan's brother Sulim Yamadayev, a former commander of the Russian Defense Ministry's Vostok battalion in Chechnya.
Yamadayev was driving his Mercedes car in downtown Moscow, when he was attacked by unknown gunmen at 5:20 pm Moscow time (13:20 GMT). The attackers shot his car and then fled the scene in an Audi 80 car, sources said.
"At 5:20 p.m. on the Smolenskaya embankment a man approached a Mercedes car, which had stopped at a red traffic light, and shot former member of the State Duma Ruslan Yamadayev, who was behind the driver's wheel at the time," said Valery Gribakin, a spokesman for the Russian Interior Ministry.
Meanwhile, a law enforcement source said Yamadayev was riding in a car with former commandant of Chechnya Lt. Gen. Sergei Kizyun. The source added that Kizyun was seriously wounded and taken to a hospital.
The source also said that obviously it was a contract killing as the assassins knew who was in the car, which they followed for some time before carrying out the attack.
Vladimir Markin, a spokesman for the Investigation Committee of the Russian Prosecutor General's Office, said a criminal case had been launched on charges of murder and attempted murder.