> DZIALDOWO, July 14 — A mass grave containing human ashes equivalent to 8,000 people has been discovered near a former Nazi concentration camp in Poland, the country’s Institute of National Remembrance said on Wednesday. The institute, which investigates crimes committed during the Nazi occupation of Poland and the communist era, said the remains were unearthed near the Soldau concentration camp, now known as Dzialdowo, north of Warsaw. Nazi Germany built the camp when it occupied Poland during World War II, using it as a place of transit, internment and extermination for Jews, political opponents and members of the Polish...