The two men, aged 32 and 34, were arrested on Wednesday on suspicion of links to the terrorist group ISIS/Daesh and had been being monitored by the PJ since 2017.
The two men were arrested in Greater Lisbon and are suspected of having joined the Islamic State militias in Mosul, the former capital of the Islamic State (EI) in Iraq.
According to a source linked to the investigation, within the scope of international judicial cooperation, these two suspects will have been in Mosul in 2016 and the evidence collected indicate that they belonged to the ranks of Daesh's militias.
The two men, who lived in the same house in the Lisbon region, were initially detained in the prison facility attached to the Judiciary Police, before being interrogated.
In a statement, the PJ said that at issue are signs of the practice of crimes of adhesion and support to an international terrorist organisation, international terrorism, and crimes against humanity.
"The evidence gathered indicates that these two individuals have taken different positions in the structure of ISIS / Daesh, and they are also the object of investigation by the competent Iraqi judicial authorities", refers the note from the Judiciary Police, stressing that for now there is no evidence that the crimes that are imputed to the two individuals had been committed in Portugal.
The operation was conducted by the PJ's National Counterterrorism Unit (UNCT), headed by Manuela Santos, and also had the collaboration of the Central Department of Investigation and Criminal Action (DCIAP), the Foreigners and Borders Service (SEF) and, at the level international, with the support of Iraqi judicial authorities, through UNITAD-UN.