MOSCOW -- Vladimir Rushailo, the secretary of Russia's Security Council and a top aide to President Vladimir Putin, was hospitalized Monday in serious condition following a car accident in which at least six people died.

Russian media reports said eight remained in hospital after the incident in Russia's far east, including the governor of Kamchatka, Mikhail Mashkovtsev, who was traveling in the same car as Rushailo.

The official RIA Novosti news agency reported that Rushailo had suffered concussion as well as injuries to his head and chest.

Television reports said the accident was caused by an allegedly drunk driver of a Jeep that crossed into the opposite lane and crashed head-on into Rushailo's entourage. The driver of the Jeep died in the crash.

Regional prosecutors in Kamchatka told Interfax News Agency that they had launched a criminal inquiry into the incident.

Rushailo was being given a brain scan in hospital to check for internal bleeding, AFP said.

There was no initial comment on the incident from Putin, who is currently vacationing in the Black Sea resort town of Sochi.

Rushailo, 49, is a life-long police officer who pioneered Moscow's fight against organized crime.

He is also seen as a close ally of controversial Russian tycoon Boris Berezovsky, living in self-imposed exile in London.