A Moscow court has charged two men in connection with the murder of Russian opposition activist Boris Nemtsov.

It said one of the men, Zaur Dadayev, had admitted involvement in the shooting on a bridge near the Kremlin on 27 February.

He and the other accused, Anzor Gubashev, are of Chechen origin.

Three other suspects remain in custody. A sixth man is reported to have killed himself in a standoff with police in the Chechen capital Grozny.

The suspect threw one grenade at the arresting officers and blew himself up with another, a security source told Interfax news agency.

Gubashev and Dadayev, who are both accused of organising and carrying out the murder, were brought into court amid heavy security.

Chechen leader Ramzan Kadyrov said Dedayev was a devout Muslim who was shocked by cartoons of the Prophet Muhammad published by the French satirical magazine Charlie Hebdo.

But tonight one of the politician`s closest allies dismissed Islamic extremism as a motive for his murder. Ilya Yashin told the BBC that Boris Nemtsov had made few comments on the cartoons. He was far better known for his sharp criticism of the Kremlin.

Kadyrov also confirmed Dadayev had been a member of the Chechen police who was decorated for his bravery.