Spain and Morocco arrested 14 people on 25 August, suspected of recruiting fighters to join Islamic State (IS) in Syria and Iraq, Spain's Interior Ministry said. Suspects were detained in the outskirts of Madrid and in other cities and towns in Morocco, it added.
The arrests were linked to "a network recruiting and sending jihadists to join the Islamic State and to combat in the conflict zone controlled by the Islamic State in Iraq and Syria," Spanish Interior Minister Jorge Fernandez Diaz told reporters.
At 12.00pm on Tuesday the police operation continued at a house in the town of San Martin de La Vega, some 35km from the Spanish capital. A police officer taking part in the operation said the suspect was inside the house where he lives with his family.
The operation comes days after a 26-year-old Moroccan man was accused of attacking passengers on a train in France, armed with a Kalashnikov, an assault rifle and a box cutter knife. Spain and other countries in Europe and north Africa have said they are alarmed about the risk of locals joining militants abroad and returning to launch attacks at home.