Rome metro line runs into Roman barracks and burial ground

An archeologist checks human bones as ancient roman ruins of former barracks were discovered during work on a new underground line, in Rome, Monday, May 16, 2016. Work on the Metro C being built through the center of Rome has once again run into ancient roman ruins, this time the barracks for the Roman Praetorian guards dating back to the period of Emperor Hadrian, in the second century A.D. Officials say the barracks cover 900 square meters, and include a 100 meter hallway with 39 rooms. (AP Photo/Alessandra Tarantino) (The Associated Press)

A view of ancient roman ruins discovered during work on a new underground line, in Rome, Monday, May 16, 2016. Work on the Metro C being built through the center of Rome has once again run into ancient roman ruins, this time the barracks for the Roman Praetorian guards dating back to the period of Emperor Hadrian, in the second century A.D. Officials say the barracks cover 900 square meters, and include a 100 meter hallway with 39 rooms. (AP Photo/Alessandra Tarantino) (The Associated Press)

An archeologist checks ancient roman ruins discovered during work on a new underground line, in Rome, Monday, May 16, 2016. Work on the Metro C being built through the center of Rome has once again run into ancient roman ruins, this time the barracks for the Roman Praetorian guards dating back to the period of Emperor Hadrian, in the second century A.D. Officials say the barracks cover 900 square meters, and include a 100 meter hallway with 39 rooms. (AP Photo/Alessandra Tarantino) (The Associated Press)

Work to upgrade Rome's public transport has again run up against an ancient problem: archaeological ruins.

Culture ministry officials on Monday showed reporters where work on the city's third subway line unearthed barracks for Roman Praetorian guards dating from the second century.

While construction workers poured concrete at the planned Amba Aradam metro stop, an archaeologist just a few meters away brushed dirt from a small bronze bracelet.

Archaeologists have also found what appears to be a collective grave at the barracks. Archaeologist Romina Mosticone says she has found 13 adult skeletons and a bronze coin.

Officials hope to incorporate the discovery into the new metro station, which is scheduled to open in 2020. Work on Rome's Metro Line C has been beset by delays since launching in 2007.