"We have broken up a network responsible for sending combatants to Al-Qaeda-linked terrorist groups operating in Syria," the Interior Ministry said in a statement.
The joint operation between the police and Civil Guard remains open and further arrests have not been ruled out.
The network is said to have been based in Ceuta and the town of Fnideq (known in Spanish as Castillejos) in bordering Morocco, according to Catalan daily La Vanguardia.
It is believed to have recruited and funded potential jihadists, planning their indoctrination and training and putting them in contact with other terrorists connected to Al-Qaeda.
In the official statement it was noted that security forces had uncovered evidence that dozens of people had travelled from Ceuta and Morocco to Syria and that at least one of them had participated in a suicide bombing.
Others are said to have joined training camps before joining front-line action.
The police and Civil Guard began investigating the network separately in 2009 and 2011 but joined forces earlier this year.