Pope Francis paid tribute on Sunday to Jews killed by the Nazis and victims of murder and deportation by the Soviet KGB, in twin visits to memorials marking the darkest periods of Lithuania's history.

On the 75th anniversary of the wartime liquidation of the Vilnius ghetto, Francis stopped to pray at a simple stone monument commemorating the 200,000 Lithuanian Jews killed either in the country or in Nazi concentration camps in Europe.

Minutes later, he paid an emotional visit to the nearby Museum of Occupations and Freedom Fights, a former KGB basement jail where Lithuanians who were considered enemies of the Soviet Union were either executed or tortured before being sent to labor camps in Siberia.