Rudi Oppenheimer, who spent 15 months in Bergen-Belsen, has warned teenagers that the world "has not learned a thing yet" about the importance of offering a home to endangered refugees.

The testimony of Mr Oppenheimer to pupils of Pimlico Academy in Westminster was live-streamed to more than 200 schools on Wednesday morning.

Students from England, Scotland and as far afield as Sweden sent questions to the survivor, whose family fled Berlin for Holland in 1936, only to be captured and transported to Westerbork transit camp in 1943.

Mr Oppenheimer, 84, said the HMD Q&A was the 1,596th time he had addressed a school group. Comparing the current refugees to the Jews who tried to escape Nazi atrocities, he pointed out: "We have problems in Darfur, Iraq, Syria, Ukraine, you name them. There are plenty of people who want to leave their country and can leave their country but no one wants them."

He recalled that while growing up, "I didn't know that the Nazis didn't like little Jewish boys such as me because my mother didn't tell me. I considered myself a German and I was very proud to be one. As far as I was concerned, everything was fine in Germany. But of course it wasn't. I just didn't know."

Answering an online question about whether he had forgiven Germany for what happened to him and his family, Mr Oppenheimer replied: "I don't hate them at all. But the forgiveness should be done by my parents. They were the ones who really suffered."

He told a questioner who asked what he thought about movies based on the Holocaust: "They're not accurate, but I love them. It gets youngsters interested in the Holocaust."