OVIEDO, Spain 

Portuguese police have arrested six alleged members of a far-right extremist group suspected of terrorism, hate crimes, and illegal weapons possession, authorities said Tuesday.

The suspects are believed to belong to the Armilar Lusitano Movement, a group seeking to establish a political movement backed by an armed militia, police said in a statement.

During the operation, officers seized various explosives, 3D-printed firearms, 3D printers, dozens of rounds of ammunition, knives, computer equipment, and propaganda materials.

One of those arrested was a municipal police officer, the Portuguese daily Diario de Noticias reported.

Police said the investigation began after they detected extremist content online linked to nationalist and radical far-right ideologies that promoted anti-system conspiracy theories and incited discrimination and violence against immigrants and refugees.

The suspects are due to appear in court later Tuesday for preliminary hearings and possible pretrial detention.

The Armilar Lusitano Movement was previously investigated by military police in 2020 after a blog associated with the group published classified navy documents under a false profile.

Although an internal probe identified the source, the case was closed without charges, according to Diario de Noticias.​​​​​​​

Portugal has seen the far-right gain ground in recent years.

After elections in May, the far-right Chega party became the official opposition for the first time in its history. Chega, however, has no known links to the Armilar Lusitano Movement.