Scientists have discovered the oldest evidence of human cannibalism in the western European Mediterranean region, by analysing 10,000-year-old bones with scratch and bite marks on them.

The bones, discovered in the Santa Maria Caves in Spain, belong to the Mesolithic period, researchers said.

The Mesolithic period lasts from about 10,200 to 8,000 years ago. The human bones were an accidental find, said study lead researcher Juan Morales-Perez, a researcher at the University of Valencia in Spain.

"I was studying the remains of Mesolithic animals from the Santa Maria site, and suddenly I identified a human distal humerus - an elbow - and it was full of cuts," Morales-Perez said.

Researchers eventually discovered 30 bones belonging to three individuals: a robust adult, a gracile adult and an infant, 'Live Science' reported.

However, the infant had only one complete bone (a shoulder blade) that did not show signs of cannibalism, the researchers said.

The bones date to between 10,200 and 9,000 years ago, Morales-Perez said. The last of the hunter-gatherer communities lived during this time, and evidence suggests that their culture was more organized and complex than it was during the Paleolithic period.

"A good example of this complexity is the appearance of the first cemeteries. There are also these strange examples of cannibalism," Morales-Perez said. The study was published the Journal of Anthropological Archaeology.