The note stayed hidden for more than 60 years
Builders working near the site of the Auschwitz-Birkenau death camp have found a message in a bottle written by prisoners, museum officials say.
The message, written in pencil and dated 9 September 1944, bears names, camp numbers and home towns of seven young inmates from Poland and France.
At least two survived the Nazi camp, an Auschwitz museum official said.
The bottle was buried in a concrete wall in a school that prisoners had been compelled to reinforce.
The school's buildings, a few hundred metres from the camp, were used as warehouses by the Nazis, who wanted them protected against air raids.
The authors of the note "were young people who were trying to leave some trace of their existence behind them", said museum spokesman Jarek Mensfelt.
The authenticity of the message has been checked by the museum.
"All of them are between the ages of 18 and 20," the final sentence of the note reads.
Alive and well
Six of the prisoners were from Poland and one was from France. The note gives the names as: Bronislaw Jankowiak, Stanislaw Dubla, Jan Jasik, Waclaw Sobczak, Karol Czekalski, Waldemar Bialobrzeski and Albert Veissid.
Of the seven, Mr Veissid is alive and well, the BBC has established, having spoken to him on the phone at his home in France.
Builders found the bottle when they where removing a layer of old cement
Mr Mensfelt said Karol Czekalski and Wachaw Sobczak had definitely survived the camp. He is at present trying to find out whether they are still alive today.
"Mr Czekalski kept in touch with the museum until some time in the 60s, then we lost contact with him," he said. "His whole family was killed in Auschwitz."
Nothing is known about the fate of the other four men who signed the note. "Maybe they were transferred to another camp," said Mr Mensfelt, "or maybe they died."
The Nazis murdered some 1.1 million people at Auschwitz - mainly European Jews, but also non-Jewish Poles, Roma (Gypsies), homosexuals and others.