(CNN) -- Police in Spain and Morocco arrested seven suspected Islamist militants who recruited and sent fighters for al Qaeda terrorist organizations in Syria and Mali, Spain's Interior Ministry said Friday.
The suspects include a Spaniard and two Frenchmen who were arrested in the Spanish enclave of Melilla on Morocco's north coast, a Tunisian arrested in the city of Malaga on the Spanish mainland and three Moroccans detained in Morocco, the ministry said.
A ministry statement said it was, to date, "the most important" breaking of a cell said to be involved in sending Islamic militant fighters to Syria.
The alleged ringleader of the cell, a Spaniard living in Melilla, Mustafa Maya Amaya, was detained. He had met in his home with two French citizens who were preparing to go to Syria to fight with al Qaeda-linked forces. They were also arrested and identified as Paul Cadic and Farik Cheikh, the ministry said.
The movement of fighters from Europe and North Africa to war zones such as Syria, and their eventual return to potentially carry out terrorist attacks, has been a prime concern for authorities battling terrorism.
Some suspects arrested in the latest operation had in fact returned home after going to conflict zones like Syria, the Interior Ministry said.
In January, a suspected Islamist militant returning to Europe from the war in Syria was arrested at the Malaga airport in southern Spain as a potential "threat to national security," the Interior Ministry said in a statement at the time.
In the latest arrests, the cell is said to have used the Internet to recruit fighters for the Jabhat al-Nusra front, described as an active al Qaeda group in and around Syria, and for the Islamic State of Iraq and Syria and al Qaeda in the Islamic Maghreb.
The cell's activities affected Spain, Morocco, Belgium, France, Tunisia, Turkey, Libya, Mali, Indonesia and Syria, the statement said.
Police began investigating the cell in 2010 and eventually had the support of the United States FBI, Spain's national intelligence service and Moroccan police, the ministry said.
The three suspects arrested in Morocco were identified as Tarik Ahnin, Soufian el Moumni and Mohamed Karraz. In Malaga, a Tunisian man accused of forging documents for the group was arrested and identified as Chafik Jalel Ben Amara Elmedjeri. He had been arrested in 2006 for alleged membership in a terrorist group, the ministry said.
Police searched various homes in Melilla, Malaga and Morocco and were expected to seek international arrest warrants for other members of this cell who are in other countries, the ministry said.
On Tuesday, Spain marked the 10th anniversary of the Madrid train bombings that killed 191 people and wounded more than 1,800.
The Spanish courts convicted 14 Islamic militants for their roles in the bombings on morning commuter trains, along with four Spaniards who trafficked in explosives used in the attacks. A further seven key Islamist suspects blew themselves up three weeks after the train attacks as police closed in on their hideout in a Madrid suburb.
Spain has arrested 472 suspected Islamic militants since the train bombings on March 11, 2004. There are more than 1,800 police and security officials dedicated to fighting terrorism, far more than at the time of the attacks, Interior Minister Jorge Fernandez Diaz said this week.
Spain is on a level two anti-terrorist alert, unchanged since 2009, on a scale of four terrorist prevention levels. Level two signifies a "probable risk" of another attack, the Interior Ministry said.