Chechen President Ramzan Kadyrov said Thursday that the murder of Ruslan Yamadayev, a former State Duma deputy and a member of a Chechen clan that challenged Kadyrov's authority, was most likely linked to a blood feud.

In his first public comments on the murder of Yamadayev, who was gunned down in central Moscow late Wednesday, Kadyrov told reporters in Grozny that he is "80 to 90 percent certain that the murder could be motivated by a blood feud," Interfax reported.

An unidentified attacker walked up and fired a pistol several times into Yamadayev's Mercedes S500 after Yamadayev stopped for a red light Wednesday evening on Smolenskaya Naberezhnaya, authorities said.

Yamadayev, 47, and his brothers headed a clan that had a falling out with Kadyrov after enjoying warm relations with Kadyrov's father, assassinated Chechen President Akhmad Kadyrov.

Kadyrov has accused Yamdayev's younger brother, Sulim, the former head of Vostok, the Defense Ministry's special commando battalion in Chechnya, of kidnapping and murder.

He suggested Thursday that Yamadayev may have been killed by relatives of Yamadayev's purported victims.

Kadyrov said he regretted Yamadayev's death. "If Ruslan Yamadayev was guilty of something, he should have been tried in court," he said.

Yamadayev's brother, Sulim, speaking at the funeral, accused Kadyrov of killing Ruslan and vowed to take revenge, Reuters reported.

Kadyrov's spokesman, Lyoma Gudayev, suggested Thursday that the assassination was an attempt to destabilize the situation in Chechnya, which Kadyrov -- with the Kremlin's backing -- has ruled with an iron fist.

"Forces that want to foment tensions in Chechnya could be interested in killing Yamadayev in such audacious fashion," Gudayev said, Interfax reported.

The main investigative department with the Investigative Committee is handling the case because of the "particular brazenness" of the crime and its "resonance," committee spokesman Vladimir Markin said Thursday, Interfax reported.

Like Kadyrov, the Yamadayevs are former Chechen separatists who fought federal forces before switching sides during the second Chechen war. And like Kadyrov, they were lavishly rewarded by the Kremlin with posts in the government and military.

But they became the target of a legal crackdown by Kadyrov in what many analysts see as an attempt to completely consolidate his power in the republic.

Several senior State Duma deputies who worked with Yamadayev when he was a lawmaker from 2003 to 2007 said his murder was linked either to his business or to clan warfare in Chechnya.

Kommersant suggested Thursday that the killer may have mistaken Ruslan Yamadayev for his brother Sulim, the Yamadayev for whom Kadyrov has reserved his harshest public words.

The two brothers were using the same car, which was registered to a relative of theirs living in Moscow, Kommersant said.