Police arrest a suspected terrorist in Ceuta on October 16. EFE

According to investigators, the suspect, who had studied up on terrorist tactics online, had no fear of legal reprisals for any attacks he might have carried out – a sign both of the threat he posed and of his membership of the so-called Islamic State (ISIS) terror group.

The man had converted to the jihadist cause after constantly viewing audiovisual material on the internet and hoped to recruit people with a range of skills to help him carry out terrorist attacks, police said.

Investigators added that the suspect had all the hallmarks of a lone wolf terrorist, including constant online activity using numerous profiles, a limited social life and the viewing and sharing of videos and publications with references to suicide missions carried out by jihadists. He had also accepted an ISIS call to take part in “individual jihad” and wage war “in the homes of the West.”

Police said the suspect had all the hallmarks of a lone wolf operative including constant online activity and no social life

The arrest came in the wake of three other similar operations of in recent days, including the detention of four suspects with possible links to the Paris terror attacks of 2015.

In related news, authorities in Germany have detained a Spanish-born German citizen who worked for German intelligence services after he allegedly made pro-jihadist statements and handed over classified information during online chats carried out using a false name.

The 51-year-old suspect, who had worked for German security forces since April, had planned to carry out attacks in the city of Cologne, according to reports in the Der Spiegel and Die Welt newspapers.

Spain has been at terror alert level four – the second-highest level – since the jihadist attacks against French satirical magazine Charlie Hebdo in January 2014.

Up to 450 citizens or residents of Spain have traveled to Syria and Iraq over the last two years to join ISIS, according to figures released recently by the Moroccan Center for Strategic Studies. That figure more than doubles the official number of Spain-based recruits estimated by the Interior Ministry, which talks about 190 individuals.