ZAGREB (AFP) - A mass grave dating from World War II and containing the remains of up to 4,500 people, including German officers and their Croatian allies, has been found near Zagreb, media reports said Saturday. Bones were found in six caves at Harmica, in the Zapresic region, some 20 kilometres (12 miles) west of the capital, close to the border with Slovenia, newspapers and state television said. The website of the daily Jutarnji List said they included soldiers of the Croation Ustachi regime allied to the Nazis and some 500 German army officers. It quoted an official of the Croatian branch of the Helsinki Committee human rights organisation, Ivan Zvonimir Cicak, as saying they were probably members of the German armys 39th Division, which comprised Croatian troops commanded by Germans. The division surrendered to communist partisans loyal to Josip Broz Tito near the town of Rijeka in early 1945. They appeared to have been executed and their bodies were thrown into the Harmica caves. The estimate of the numbers of bodies is based on the testimony of witnesses, and Cicak said that other mass graves could be found in the same region. Hundreds of thousands of Serbs, gypsies and Jews were massacred by the Ustachis until the regime was overthrown by the partisans under Tito, who went on to become ruler of Yugoslavia.