Two of five suspects in the killing of Russian opposition leader Boris Nemtsov have been charged with murder and one has confessed, a judge in Moscow said Sunday.

Zaur Dadaev and Anzor Kubashev were formally charged at the hearing Sunday. Judge Nataliya Mushnikova said Dadaev confessed his involvement to the police, Russia’s RT news service reported. Dadaev, speaking from a defendant’s cage in the courtroom, didn’t comment on the confession but asked for a fair trial.

Russian law enforcement officers announced Saturday they had detained suspects from the North Caucasus Nemtsov’s death. Federal Security Service director Alexander Bortnikov said Dadaev served with Interior Ministry troops in volatile Chechnya in the North Caucases while Kubashev worked for a private Moscow security firm.

The other three suspects are Kubashev’s brother Shagit, Ramzat Bakhaev and Tamerlan Eskerkhanov, RT said. The charges sought against them were being reviewed by another judge.

Authorities have not revealed what evidence led to the arrests. No alleged motive has been announced.

Nemtsov, 55, an outspoken critic of Russian President Vladimir Putin, was shot and killed Feb. 27 as he was walking with a female companion near the Kremlin and Red Square.

« The suspects denied their ties to the crime, but we have evidence of their guilt, » an investigator told the court, citing forensic evidence and eyewitness accounts.

The three men denied their involvement, with Eskerkhanov claiming to have an alibi, RT reported.

Anna Duritskaya, who was with Nemtsov when he was shot, has returned to her native Ukraine but told investigators she would assist the investigation and return to Moscow if necessary, the Russian news agency Tass reported.

Nemtsov rose to prominence in the 1990s as a leader in the drive for capitalism. His fortunes sagged with the emergence of Putin as a political force in the country. His sway had been marginalized — and Putin’s popularity rose — as Russia became more involved in supporting ethnic Russians in Ukraine.

Nemtsov was in Moscow to organize a protest against Russia’s involvement in Ukraine and the nation’s current economic crisis. Some of Nemtsov’s supporters and colleagues have pressed for a thorough and open investigation of his death.

« For the time being, it’s very skimpy information, which tells us little, » former prime minister Mikhail Kasyanov, who has joined the opposition movement, told Interfax news agency. « But it’s good that the first results of the investigation (have) appeared. »

Contributing: Anna Arutunyan in Moscow