Madrid (AP) – Police have dismantled what they say is the Europe Union’s first clandestine underground cigarette factory, four meters (13 feet) under a horse stable in southern Spain.

Statements from Spanish police and Europol said 20 people from Britain, Ukraine and Lithuania were arrested.

Europol said beds and living quarters for the workers were found in the bunker factory in southern Málaga province. Access to the plant, operating since 2019, was concealed by a cargo container, police said.

EuropoI said workers were forced to labor in extremely dangerous and toxic conditions and were not allowed to leave the facility on their own. It said the factory had a complete production line and produced 3.500 cigarettes an hour.

More than 3 million cigarettes, quantities of hashish and marijuana, as well as three weapons, were seized.