Although some early depictions of deities seem to appear in the art of the Indus Valley Civilisation, very few religious artifacts from the period corresponding to the Indo-Aryan migration during the Vedic period remains. It has been suggested that the early Vedic religion focused exclusively on the worship of purely "elementary forces of nature by means of elaborate sacrifices", which did not lend themselves easily to anthropomorphological representations. Various artefacts may belong to the Copper Hoard Culture (2nd millennium CE), some of them suggesting anthropomorphological characteristics. Interpretations vary as to the exact signification of these artifacts, or even the culture and the periodization to which they belonged.