Workers renovating a rugby stadium have uncovered a vast complex of tombs beneath Rome that mimic the houses, blocks and streets of a real city, officials said Thursday as they unveiled a series of new finds here.

Culture Ministry officials said that medieval pottery shards in the city of the dead, or necropolis, show the area may have been inhabited by the living during the Dark Ages [HNN Editor: sic] after being used for centuries for burials during the Roman period.

It is not yet clear who was buried in the ancient cemetery, but archaeologists at the still partially excavated site believe at least some of the dead were freed slaves of Greek origin.

"It's a matter of a few weeks to discover what is down there," said archaeologist Marina Piranomonte. "But it's something big; it looks like a neighborhood."