Workers building a new railway in London have unearthed 13 skeletons thought to be victims of the Black Death plague that swept through Europe in the 14th century, archaeologists said on Friday.

The remains were dug up at Charterhouse Square in central London during excavation work for the city's £15 billion ($22.7 billion, 17.4 billion euro) Crossrail project.

Archaeologists believe the site could be the location of a plague cemetery described in medieval records, where up to 50,000 victims of the Black Death were buried.

The plague wiped out a third of Europe's population between 1348 and 1353.

"The depth of burials, the pottery found with the skeletons and the way the skeletons have been set out all point towards this being part of the 14th century emergency burial ground," said Jay Carver, Crossrail's lead archaeologist.

"This is a highly significant discovery and at the moment we are left with many questions that we hope to answer.

"We will be undertaking scientific tests on the skeletons over the coming months to establish their cause of death, whether they were plague victims from the 14th century or later London residents, how old they were and perhaps evidence of who they were."

Records refer to a burial ground in London's Farringdon area, where Charterhouse Square is located, that opened in 1348.

The 13 skeletons were found over the last two weeks, laid out in two rows several feet below road level.

They will be taken to the Museum of London Archaeology for laboratory testing and possibly carbon-dating to try to establish their burial dates.

Scientists are hoping to use the skeletons to map the DNA signature of the plague, in research they hope could help combat modern diseases.

"Many biologists are researching ancient diseases in the hope of better understanding the modern ones," said Carver.

These are not the first skeletons found during the construction of London's Crossrail.

Archaeologists have already uncovered more than 300 skeletons dating from the 16th to 19th centuries, near the former site of the notorious "Bedlam" psychiatric hospital in east London.

The Crossrail line, under construction since 2009 and due to carry its first passengers in 2017, will run across London on an east-west route.

It will be mostly overground but will run underground through the city centre.