From Spain, they used the Internet and social media to recruit and indoctrinate young, potential Islamist militants to work for ISIS.
They even attracted Facebook followers as far away as Latin America, the United States, Belgium and France.
But on Tuesday, Spain’s Civil Guard forces arrested four suspects in different parts of the country suspected of recruiting for ISIS, the Interior Ministry said in a statement.
Two key suspects were arrested in the Spanish enclave of Melilla, on Morocco’s north coast — where previous arrests for Islamist militant activity have occurred.
Those two, who were not immediately identified by authorities, translated ISIS material to Spanish, and their recruitment targets included women.
In addition to using the Internet, the two key suspects also held discreet meetings in homes, showing the latest ISIS videos to recruits, the Interior Ministry said. The statement also said some recruits were preparing to travel to conflict zones.
The other two suspects were arrested near Barcelona and in the province to the north, Girona.
The Interior Ministry said one of them edited and distributed recruitment videos, and the other was more of a “lone wolf” who had consumed indoctrination material and started a campaign to persuade others.