Russia detains 4 suspects over Nemtsov killing

Four men were in custody Sunday for the killing of Russian opposition activist Boris Nemtsov in a probe which has yet to reveal the motive for the brazen assassination in the centre of Moscow.
The suspects, from Chechnya in the volatile northern Caucasus region, were detained a little over a week after Nemtsov, a longtime critic of President Vladimir Putin, was shot four times in the back as he strolled with his girlfriend along a bridge in full view of the Kremlin and Red Square.
The FSB federal security service and powerful Investigative Committee, which are working together to solve the murder that Putin denounced as a "provocation," on Saturday announced the arrests of Zaur Dadayev and Anzor Gubashev.
Late Saturday Albert Barakhoyev, secretary of the Security Council of Russia's Ingushetia republic, told state news agency RIA Novosti the men had been arrested in the republic, which borders Chechnya, along with Gubashev's younger brother and another person.
State news agencies reported that Dadayev was a deputy commander for the Chechen police while Gubashev worked for a private security company in Moscow.
The suspects were due to appear in court in central Moscow on Sunday, where security had been stepped up, to determine whether to extend their detention, court spokeswoman Anna Fadayeva told the news agency. It was not clear if all four men would be appearing.
However no information has emerged as to the possible motive the men could have had in killing the charismatic opposition leader. His allies believe his assassination was a hit ordered by the top levels of government determined to silence dissenters. The allegation has been strenuously denied.
The mother of Dadayev was stunned at the arrest of her son.
"I was informed today that my son Zaur Dadayev has been detained on suspicion of involvement in Boris Nemtsov's murder. I can't believe it. He could not have committed this crime," Aaimani Dadayeva told the Interfax news agency late Saturday.
- Russia has 'crossed the line' -
The audacious murder in one of the most secure parts of the Russian capital sent shivers through an opposition which has seen several critics of the Kremlin killed in recent years and accuses Putin of steadily suppressing independent media and opposition parties.
Nemtsov's daughter Zhanna Nemtsova, in an interview with CNN from Germany, said the murder was obviously "politically motivated."
"In an authoritarian regime, any person who does not agree with politics -- who criticises the official standpoint -- is dangerous," Nemtsova said.
"I think that now, Russia has crossed the line after this murder, and people will be frightened to express their ideas which contradict ... the official standpoint."
Her comments echo that heard from Kremlin critics since the killing such as activist Alexei Navalny, who accused "the country's political leadership" of ordering a hit on Nemtsov.
Nemtsov had long complained of being followed and having his phone tapped.
Putin has described Nemtsov's murder as a tragedy that brought disgrace on Russia and vowed that everything would be done to bring to justice those who committed a "vile and cynical murder."
- Fifth column -
Many Russians say that failing direct involvement, Putin is to blame for whipping up hatred against the opposition by regularly referring to them as a "fifth column" of traitors and spies -- a message spread by all-powerful state media.
"It's probably hard to give a scientific definition where the opposition ends and the fifth column begins," Putin said at his annual news conference in 2014 after being questioned on his use of the term.
He first used the term fifth columnist -- which originated during the Spanish civil war and refers to a group of people undermining a nation from within -- after last year's annexation of Crimea which plunged Russia's relations with the West to Cold War lows.
Investigators have suggested Nemtsov's killers wanted to destabilise Russia while politicians have referred to a western plot.
But investigators are also probing the possibility he was assassinated for criticising Russia's role in the Ukraine conflict or his condemnation of January's killings at the Charlie Hebdo satirical weekly in Paris by Islamist gunmen.
At the time of his death, Nemtsov was believed to be working on a study detailing the presence of Russian troops in Ukraine, a claim the Kremlin denies.