MOSCOW — A Russian human-rights lawyer whose killing on a central Moscow street has spotlighted the risks faced by Russians who fight for justice was buried Friday, and the U.S. Embassy said it was outraged by the crime.

Rights activists have compared Monday's murder of Stanislav Markelov to the 2006 slaying of investigative journalist Anna Politkovskaya. Anastasia Baburova, a reporter from Politkovskaya's Novaya Gazeta newspaper who accompanied Markelov, was also fatally shot by a masked assassin on a street near the Kremlin.

The U.S. Embassy said in a statement Friday that it was "saddened and outraged" by the murders. "We hope that those responsible will be caught, tried and punished, and that the long series of unsolved murders of journalists will come to an end," it said.

Markelov was buried Friday at the Ostankino cemetery in northern Moscow under icy rain.

Rights activist Lev Ponomaryov said the killing of Markelov was a political murder and yet another signal of Russia sliding back toward repressive Soviet ways.

"The murder shows we are in a post-totalitarian state that is returning to its old ways," Ponomaryov told The Associated Press. "There have been political murders, and they will continue."

Markelov was killed minutes after a news conference at which he talked about his efforts to fight the early release of a Russian army colonel convicted of killing a Chechen woman in 2000. Col. Yuri Budanov was released from prison last week with more than a year left in his 10-year sentence.

Markelov was working with the victim's family to put Budanov back behind bars, and he reportedly received death threats from Budanov's supporters days before the attack.

Some Russian commentators said, however, that the Budanov angle could be a smoke screen.

Markelov also had defended Mikhail Beketov, the editor of a suburban Moscow newspaper who had been charged with slandering local authorities amid crusades against environmentally threatening development projects. Beketov was brutally beaten by unidentified assailants in November and remains in a coma.

Markelov had said he knew who attacked Beketov, and claimed local officials were behind it.

Russian media also have speculated that neo-Nazi groups could have been behind Markelov's shooting.

He was beaten in Moscow in 2004, around the time he was representing victims of beatings by ultra-nationalists, and had since received further threats from skinheads.