Two men arrested over killing of Russian opposition figure Boris Nemtsov

One of the suspects in the killing is taken into custody
One of the suspects in the killing is taken into custody

Two men have been formally charged over the killing of prominent Russian opposition figure Boris Nemtsov.

A hearing for three other suspects was also under way in Moscow, a court spokeswoman said.

Anna Fadeeva told reporters at the Basmanny court house in Moscow that Zaur Dadaev and Anzor Gubashev had been charged. She did not specify the charges.

Dadaev and Gubashev were identified as suspects by federal security service director Alexander Bortnikov a day earlier. Until three other men were also brought to the court today, there had been no official confirmation of other suspects.

Mr Bortnikov gave no details of how the men were detained or specifics on how they were connected to the killings.

However, the state news agencies Tass and RIA Novosti said the pair were detained in Ingushetia, a republic bordering Chechnya, citing Ingush Security Council chief Albert Barakhoev.

Dadaev served in a battalion of Interior Ministry troops in Chechnya, Mr Barakhoev said.

He said the other, Gubashev, had worked in a private security company in Moscow.

There was scant information about the identity of the three other suspects. Mr Barakhoev was quoted by RIA Novosti as saying two others were seized at the same time as Dadaev and Gubashev. But there had been no official announcement of their detention.

Shortly before the court session began, Investigating Committee spokesman Vladimir Markin revealed there was a fifth suspect, but gave no details.

Mr Nemtsov's killing shocked Russia's already beleaguered and marginalised opposition supporters. Suspicion in the opposition is high that the killing was ordered by the Kremlin in retaliation for Mr Nemtsov's adamant criticism of President Vladimir Putin. Mr Nemtsov, 55, was working on a report about Russian military involvement in the eastern Ukraine conflict.

But Russia's top investigative body said it was investigating several possible motives, including that he was killed in an attempt to smear Mr Putin's image. It also said it was looking into possible connections to Islamic extremism and Mr Nemtsov's personal life.

Many believe that Mr Nemtsov's death in a tightly secured area near the Kremlin wouldn't have been possible without official involvement, and could be an attempt to scare other government foes.

Mr Putin, who had dubbed Mr Nemtsov's killing a "provocation," made no comment on the detentions.