Madrid: Spanish Interior Minister Jorge Fernandez Diaz confirmed from Brussels on Friday that two more people had been detained in Spain for their possible relationship with the Islamic State (IS).

This is the second operation against would-be jihadists in December after a man was arrested in Pamplona as he prepared to travel to Syria, Xinhua reported.

The arrests took place at the Martutene prison in the Basque province of Gipuzkoa in the north of Spain, where both of those detained were already serving sentences for minor offences.

One of those detained was a 24-year-old Moroccan, while the other was a 32-year-old from the Basque town of Zumarraga. The interior ministry did not rule out making further arrests as investigations continue.

One of the signals which apparently altered security forces is that one of the pair posted a video of himself burning his passport on the internet. This is a ritual carried out by many jihadists to show their willingness to travel to Syria to fight for the IS.