Flowers float in a lake after an event at the former Nazi concentration camp Ravensbrueck in Fuerstenberg, northeastern Germany, Sunday, April 19, 2015 to commemorate the 70th anniversary of the liberation of the camp by the Red Army on April 30, 1945.

Flowers float in a lake after an event at the former Nazi concentration camp Ravensbrueck in Fuerstenberg, northeastern Germany, Sunday, April 19, 2015 to commemorate the 70th anniversary of the liberation of the camp by the Red Army on April 30, 1945. Image by (AP Photo/Ferdinand Ostrop)

Officials in Germany are solemnly commemorating the liberation of two Nazi concentration camps 70 years ago in the closing days of the Second World War.

Poland’s first lady, Anna Komorowska, joined in remembrance activities at the site of the Ravensbrueck women’s camp in northern Germany. Many of the prisoners came from Poland.

Ceremonies also were taking place at the former Sachsenhausen camp near Berlin.

Poland's First Lady, Anna Komorowska, Annette Chalut, camp survivor and President of the International Ravensbrueck Committee, and Germany's First Lady Daniela Schadt, from left, plant roses during an event at the former Nazi concentration camp Ravensbrueck in Fuerstenberg, northeastern Germany.

Poland’s First Lady, Anna Komorowska, Annette Chalut, camp survivor and President of the International Ravensbrueck Committee, and Germany’s First Lady Daniela Schadt, from left, plant roses during an event at the former Nazi concentration camp Ravensbrueck in Fuerstenberg, northeastern Germany. Image by (AP Photo/Ferdinand Ostrop)

The US Holocaust Memorial Museum said 30,000 to 50,000 people died at Sachsenhausen, where inmates included Jews, Poles, Soviet prisoners of war and opponents of the Nazis. More than 130,000 women were imprisoned in Ravensbrueck and 20,000 to 30,000 died there.

Sachsenhausen was liberated on April 22 1945, Ravensbrueck on April 30. Beforehand, Nazi officials forced thousands from the camps into death marches that killed many inmates.

(Press Association)