MOSCOW (Reuters) - Russian authorities detained six prison guards on Monday after a video circulated online that shows at least 10 guards torturing and beating an inmate.

The Novaya Gazeta newspaper published the 10-minute clip on Friday and said the incident took place in June 2017 in a prison in the city of Yaroslavl northeast of Moscow. Its release provoked an outcry from rights activists and journalists.

Rights groups say such abuse by prison guards is common but it rarely stirs public outrage. The government denies there is a systemic problem and says specific complaints of abuse are investigated by relevant authorities.

Investigators said they have opened a criminal investigation and said prison employees at the facility in question had punched and kicked an inmate and struck him with an object across his body, arms and legs.

Investigators said in a statement the guards were detained for “abusing their authority by using violence”. The investigators had identified all those responsible and were working on detaining other suspects.

Seventeen guards at the prison have been suspended, Sergei Baburkin, a regional human rights ombudsman, was cited as saying by TASS news agency on Sunday.

The date and location of the video could not be independently verified.

Authorities did not say if the clip was genuine or who shot it. They did not give the names of those under investigation or say if they had been charged.

It was not immediately possible to obtain comment from those detained or their representatives.

Novaya Gazeta named the inmate and said it obtained the video from his lawyer, Irina Biryukova, who works for the Public Verdict rights group. The newspaper said Biryukova told them a year ago her client had been tortured.

The newspaper said she appealed to investigators, prosecutors and prison officials over injuries he had sustained, but no action had been taken.

Public Verdict said on Monday there was a risk of reprisals against Biryukova and had decided she would remain abroad while investigators examined an appeal for state protection for herself and her family.