BERLIN (Reuters) - A vintage engine steamed into Berlin on Sunday, hauling carriages filled with photos of smiling children and poignant last letters to loved ones -- the images and words of the youngest victims of the Nazi Holocaust.
About 160,000 have visited the train, a memorial to the millions of Jews and others carried off to their deaths by Adolf Hitler's railways in World War Two.
The train set off across Germany in November on an often tearful journey due to end, like so many of the Nazis' victims, at the notorious Auschwitz death camp in Poland
With just days to go before the "train of commemoration" terminates its journey on May 8 -- the day the war ended in Europe -- it has become embroiled in a major row.
Germany's current rail operator, state-owned Deutsche Bahn, refused to allow the train to halt in the capital's central station, offering instead the eastern Ostbahnhof.
Some critics have compared the heads of Deutsche Bahn with those of the Nazi-era Reichsbahn, which deported many of the 6 million Jews who died in the Holocaust.
Left Party parliamentarian Petra Pau said the "blockade" by the firm, and the travel charges it had imposed on the train were a reminder of the difficulties still faced when trying to shed light on Germany's past crimes.
"The horror of the Nazi regime cannot be forgotten. It would be a betrayal of the victims and the future," said Pau, a deputy speaker of the Bundestag lower house.
Demonstrations, protests by Holocaust survivors and pressure from politicians including Berlin's mayor have not swayed Deutsche Bahn. The company said a stop in the Hauptbahnhof would have caused traffic chaos during the train's 10-day Berlin stay.
But it has not prevented the train making its point.
"I'm just happy...these children could be brought back from the quagmire of the past into the public eye, and their dignity restored, at least to some degree," said 84-year-old Herbert Shenkman, who survived deportation.
Defenders of the rail operator point out that Deutsche Bahn has already organised exhibits documenting the Reichsbahn's role in the genocide, and that the Hauptbahnhof -- newly built on the site of an old station -- is not integral to the history.
"The train of commemoration should continue its journey," wrote daily Die Welt. "But without all the rumblings that only serve the posturing of those who organised it."
Rose Braun, a 63-year-old Berliner, said the project, staged by a citizens' initiative, was "very late, but very important."
"Very few firms have admitted to their past -- let alone actually made an effort to come to terms with it," she said. "I hope the turn-out here today gives the Bahn pause for thought."
Organiser Hans-Ruediger Minow said the idea came about after Deutsche Bahn blocked an earlier effort to mark deportations.
"Time and again there are very painful moments on the train," he said. "In particular, Germans born at the end of the war often start to cry, especially the men. That's when they see their parents hid the truth and covered up these crimes."