Archaeologists in northern France have stumbled upon two mass graves dating back to the years of civil strife unleashed after the French Revolution of 1789, officials said Monday.

Located in a park in the city of Le Mans, the graves contain the bodies of some 30 people including several women, two male teenagers and a child, the INRA archaeology institute said in a statement.

All were identified as victims of a massacre that took place on Dec. 12 and 13, 1793, as republican forces repelled royalist Catholic rebels from the city of Le Mans, during the first War of the Vendee.

The first grave contained nine or 10 bodies, some still wearing shirt buttons and boot buckles, or carrying knives, while the second, sealed shut with a thick layer of lime, contained some 20 bodies.

All bore the signs of an extremely violent attack, with broken leg, jaw and shoulder bones, according to INRA.

Between 1793 and 1796, the fervently Catholic Vendee region on France's Atlantic coast was rocked by a drawn-out insurrection aimed at reversing the French Revolution.

At the end of the first uprising, Catholic forces were crushed and repelled from Le Mans on Dec. 12, 1793, and republican forces unleashed bloody reprisals on prisoners and rebels who were left behind.

The graves were discovered during a dig to make way for a new cultural centre.