Russian President Vladimir Putin has strongly denounced Soviet-era political repressions, describing them as a crime that should never be forgotten.
Speaking at the opening of a memorial to the victims of purges, Mr Putin said: "Political repressions have become a tragedy for our people, for the whole of society, a cruel blow to our people, our roots, culture and self-awareness.
"We are still feeling the consequences of that today."
He said "millions of people were declared enemies of the people on absurd and unfounded charges, executed, mutilated and went through suffering in prisons and labour camps".
Mr Putin emphasised that "there could be no justification for those crimes", adding: "The horrible past can't be erased from the nation's memory."
The statement is the strongest condemnation yet of Soviet-era repression from Mr Putin, who has taken a cautious line on the nation's history, trying to focus on Soviet achievements rather than on communist crimes.
The condemnation of the purges contrasts with some other moves by authorities that Kremlin critics have seen as attempts to whitewash the image of Soviet dictator Josef Stalin.
Over recent years, many in Russia have been dismayed by government-sponsored school textbooks that painted Soviet dictator Josef Stalin in a largely positive light and by the reconstruction of a Moscow subway station that restored old Soviet national anthem lyrics praising Stalin, as part of its interior decoration.
Kremlin foes saw such moves as attempts to whitewash Stalin's image and part of Mr Putin's rollback on democracy.
While denouncing Soviet-era repressions, he also used the occasion to emphasise the need for political stability.
"We and our descendants should remember about the tragedy of the repressions, about the reasons behind them, but it doesn't mean making calls for settling scores," he said.
"We mustn't again push society toward dangerous confrontation. It's important for us to rely on values of stability and trust."
Russian Orthodox Church Patriarch Kirill, who attended the opening of the memorial in central Moscow alongside Mr Putin, said the new monument should help assess the nation's past and heal the nation's wounds, noting this is particularly important as the nation marks the centenary of the 1917 Bolshevik revolution next month.
"Remembering the tragic moments of our history, people mustn't feel gloom and despair, they must think about their descendants and the country they will leave to them," he said.