Serbian archaeologists have found a 7,500-year-old copper axe in a Serbian town of Prokuplje that suggests that the Copper Age began earlier than believed.

"Until now, experts said that only stone was used in the Stone Age and that the Copper Age came a bit later. Our finds, however, confirm that metal was used some 500 to 800 years earlier," said archaeologist Julka Kuzmanovic-Cvetkovic.

Copper Age is significant because it marks the first stage of human use of metal.

At another site in Plocnik discovered in 1927 archaeologists found furnace and melting pots laced with copper.

"All this undeniably proves that human civilization in this area produced metal in the 5th millennium BC," said archaeologist Dusan Sljivar.

Previously it was thought that the Copper Age started around the 4th millennium BC in southeastern Europe and the Middle East.

Plocnik is part of thew Vinca culture which is Europe's biggest prehistoric civilization that flourished in present day Serbia between 6th and 3rd millennium BC.

The culture is named Vinca after a village by the same name near Belgrade where a nuclear facility is located.