The four arrested people are in their 20s and were arrested in the Reykjavik region.
That task force took part in the police operation together with the police in the capital area.
Two of those arrested were considered armed and dangerous.
They were able to be arrested quickly and efficiently, but according to the Icelandic police, it is a relief that no one was injured in the police operation.
The investigation concerns organized crime and large-scale arms trafficking, the Icelandic police write in a press release.
The investigation is led by the Inspector General's Office of the Icelandic police, which deals with crimes related to treason and crimes against the state constitution.
The text is updated