Bulgarian archaeologists discovered a Christian necropolis outside the ruins of the medieval fortress near the rock sanctuary of Perperikon, located in southern Bulgaria near the town of Kardzhali.

The team lead by Nikolay Ovcharov found 15 tombs dating back to the 14th century, most likely the resting place of the fortress' defenders executed following its siege by Turkish emir Orhan in 1362.

"I have been exploring medieval necropolises for 15 years, but this is the most dramatic and emotional find," said archaeologist Hitko Vachev, who discovered the necropolis.

The find gives additional weight to the claims that Ottoman troops have perpetrated massacres during their invasion of the Rodopi region.

The city of Perperikon has been inhabited since around 5000 BC, while a nearby shrine dedicated to Orpheus, near the village of Tatul, dates back to 6000 BC and is older than the Pyramids of Giza.

It has fallen into disuse after the Ottomans swept through the area in the 14th century.