Spanish police have smashed a counterfeiting ring that fed around 30,000 euros in forged notes into the economy each week, arresting nine mainly Spaniards and Senegalese, police said Friday.

The network was "one of the most active given its weekly capacity for introducing counterfeit notes," police said in a statement.

The 20- and 50-euro denomination notes were brought from Italy to Spain's north-eastern Catalonia region where they were circulated in Spain's economy and that of African nations, the statement said.

Those arrested include the network's ringleaders. "Most of them are of Spanish and Senegalese origin," it said.