Reuters: Russian authorities said on Sunday they were holding five men over the killing of Kremlin critic Boris Nemtsov, one of whom served in a police unit in the Russian region of Chechnya, according to a law enforcement official.

The five men were frogmarched into a Moscow courtroom on Sunday, forced by masked security officers gripping their bound arms to walk doubled over, a Reuters reporter at the court said. They stood in metal cages in the courtroom as television crews were ushered in to film them.

A judge ruled that all five should be held in custody and said that one of them, Zaur Dadayev, had admitted his involvement in the killing when questioned by investigators.

Dadayev served for a decade in the “Sever” police battalion, part of the interior ministry in Chechnya, Russian news agencies reported. They cited Albert Barakhayev, a senior security official in the neighboring region of Ingushetia, where several of the men were detained.