Two inmates have been found dead in a penal colony in Russia's Siberian region of Zabaikalye, where guards have been previously accused of torturing inmates.

The Federal Penitentiary Service (FSIN) says the two men were found dead on August 7 "without traces of violence on their bodies" in the Corrective Colony No 5 in the city of Chita.

In recent days, three inmates in the same colony complained that guards beat and tortured them and other inmates using electric shocks.

The allegations followed the release of a video showing at least 17 guards severely beating an inmate at another Russian prison, in the city of Yaroslavl, that caused a public outcry.

Last month a local court ordered the arrest of 11 prison guards at Yaroslavl's Corrective Colony No. 1 and put one guard under house arrest for alleged involvement in the beating of Yevgeny Makarov.

Video footage of the abuse was published online last month by Russia's Novaya Gazeta newspaper and circulated widely on social media and other websites.

The Public Verdict rights organization said it was shot at the penitentiary last year.

Russia's Federal Penitentiary Service announced on July 24 that it will investigate all complaints from 2017 of violence by authorities at prisons across Russia.

United Nations human rights experts have urged the Russian authorities to prosecute cases of torture in prisons and labor camps -- including beatings, electric shocks, and suffocation.