Michelle Obama, daughters tour Berlin historic sites

US First Lady Michelle Obama and daughters Malia and Sasha on Wednesday visited key sites of Germany's troubled Nazi and Cold War history, walking through the haunting Holocaust Memorial and laying flowers for those killed at the Berlin Wall.

As President Barack Obama attended to matters of state during a 24-hour visit to the German capital, his family went on a whirlwind tour in an armoured limousine on their first visit to the city, where 8,000 police secured the presidential visit.

Dressed in light summer clothes on a blistering hot day, they were joined by the president's half-sister Auma, who studied in Germany and lives in Kenya, and Joachim Sauer, the husband of Chancellor Angela Merkel.

Their first stop was the Memorial to the Murdered Jews of Europe. Opened in 2005 near the Brandenburg Gate, the field of 2,700 concrete slabs of varying height evokes a cemetery and serves as a memorial for the millions of Jewish victims of the Holocaust.

The Obamas walked along pathways that descend into the heart of a claustrophobic maze, then visited a subterranean information centre on the millions murdered by the Nazis.

They next went to Checkpoint Charlie -- the best-known border crossing, where US and Soviet tanks once faced off -- and visited a panoramic display by artist Yadegar Asisi which offers a glimpse at what life along the Wall was like.

A large panorama inside a circular building gives a photorealistic view of a divided 1980s Berlin neighbourhood, showing the graffiti-covered West side of the Wall and, beyond the guard dogs, barbed wire and search lights, the drabness of East Berlin.

At the Wall checkpoint, the Obama family was joined by 64-year-old "First Husband" Sauer -- who, like Merkel, lived in the former communist East Germany.

"There were some very human moments," Vienna-born artist Asisi later told AFP. "It was a very relaxed atmosphere and we talked for almost an hour."

"Mr Sauer told stories and Mrs Obama asked many questions."

He said the daughters, 12-year-old Sasha and Malia, 14, had also shown a lot of interest, adding: "Little Sasha said that this was all very sad."

The group then visited the Berlin Wall Memorial, a remaining 220-metre (720-foot) section of the 155-kilometre (95-mile) "death strip" that split the city between 1961 and 1989.

They climbed an outlook platform and viewed fortifications of the Wall, where at least 136 East Germans died during escape attempts.

Michelle and the girls placed red and yellow roses in remembrance of the victims.

The final stop was the Reichstag, which housed the assemblies of the German Empire, Weimar Republic and Nazi Germany until it was destroyed by fire in 1933, leaving it abandoned for decades.

Refurbished after Germany's 1990 reunification by architect Norman Foster, who added its characteristic glass dome to symbolise open democracy, it has since 1999 housed the lower house of parliament, the Bundestag.

The president gave a speech at Brandenburg Gate on the theme of "peace and justice", but he quipped about his family: "You may notice that they are not here.

"The last thing they want to do is to listen to another speech from me. So they're out experiencing the beauty and the history of Berlin."

Meanwhile, his wife and daughters, possibly exhausted from the summer heat, settled for a rest in their luxury Ritz Carlton Hotel, scrapping a scheduled shopping trip.