Construction workers have uncovered at least 36 bodies in the central city of Kassel, police said Wednesday, which city officials believe could be the remains of slave laborers from a Nazi armaments factory. The first four skeletons were found last week at a construction site at the University of Kassel, said police spokeswoman Sabine Knoell. Another 26 were found on Monday and Tuesday, and a further six to seven were being unearthed Wednesday, she said. "It could well be that more skeletons will be found," she said. "We are prepared for anything." Some of the remains appeared to have been laid out in rows, though that was not always the case, she said. According to preliminary exams by the coroners' office, the corpses are somewhere between 50 and 100 years old. Knoell would not speculate, however, on whether they could have died during wartime bombing or were possible victims of Nazi crimes. "But we are, naturally, in contact with historians," she said. The area where the skeletons were found was home to a factory that built locomotives and tanks during World War II, where thousands of slave laborers were forced to work by the Nazis, said Kassel archivist Frank-Roland Klaube. The evidence speaks against them being factory workers buried quickly after an Allied bombing attack, he said. "Among other things, there were no rings or watches found on the corpses," he said. It is also known that in other areas of Kassel the SS shot and hastily buried other victims in the final days of the war, Klaube said. Still, there have been no reports of mass murders on the site of the new discovery, he added. The area was the site of a military hospital until 1870, and it could be that the bodies were people who died there, he said. But that would mean that the bodies are older than it is currently believed. Experts are testing the remains to try to determine how and when they died, Knoell said. "We are very curious to see what the experts find," she said. Results are not expected until next week at the earliest.