Russia's leaders are using Stalin-era tactics against the opposition including show trials and camp sentences, one of its most authoritative rights groups warned Tuesday.

Memorial rights group slammed the treatment of activists after two members of the Pussy Riot feminist rock group were sent to prison camps for a protest against President Vladimir Putin and several protest leaders were charged in criminal probes.

"The events of recent weeks show that in its dialogue with the opposition, the Russian authorities intend to rely on the language of repression -- arrests, courts, camps," Memorial said.

Its statement came during annual events in Russia to remember the victims of political repression, including a reading outside the Lubyanka security service headquarters of the names of victims killed during the purges under Josef Stalin's rule.

"Once again, as in the 1920s and 1930s, the experience of fabricating political show trials is in demand," Memorial commented. "Once again Russia is being pushed onto its usual and tragic path."

Russia's leaders seem to have no sense of history repeating itself, Memorial said.

"We are not addressing the historical responsibility of our government leaders. They are apparently lacking this feeling."

Both President Vladimir Putin and his predecessor Dmitry Medvedev have spoken out against Stalin-era repression but only sporadically and Russia has resisted opening up its archives from the period.

In a rare comment in 2007, Putin called the deaths of those killed in purges a "particular tragedy" for Russia, while Medvedev as president called for a programme of de-Stalinisation.

Little progress has been made on de-Stalinisation, Memorial's chairman Arseny Roginsky said Tuesday.

"We can talk about powerful political opposition, since the programme is based on freedom, and our life is moving in the other direction."

Under Stalin's rule, millions were imprisoned in a vast camp system and hundreds of thousands shot in purges against those perceived as disloyal to the regime. Nevertheless he is revered by some Russians, particularly as the wartime leader.

Memorial was founded in 1989 and has developed dual roles of keeping alive the memory of Stalin-era repression and fighting for current rights causes.