From the 7th century BC onwards, bronze was replaced by iron, and only jewelry and art objects were still made out of bronze. The bronze culture of the Illyrians, an ethnic group with a distinct art form, started to organize itself in what is today Croatia, Serbia, Bosnia and Herzegovina. Different Illyrian tribes, under the influence of Halstat cultures from the North, formed original regional centers. With the notable exception of Pod near Bugojno in the upper valley of the Vrbas River, nothing is known of their settlements. In eastern Bosnia in the cemeteries of "Belotić" and "Bela Crkva", the rites of inhumation and cremation are attested, with skeletons in stone cists and cremations in urns. Metal implements appear here side by side with stone implements. Most of the remains belong to the Middle Bronze Age.