Four suspects have been arrested over alleged plans for a terrorist attack in Iceland, say police.
Several semi-automatic weapons -- some 3D printed -- were seized from nine different locations, along with a large quantity of ammunition, computers, telephones and digital media.
Violence is extremely rare in the tiny European country, which has topped the Global Peace Index since being included in its rankings in 2008.
Police said four Icelanders in their 30s were arrested in Kopavogur, a suburb of the capital Reykjavik, and the southwestern town of Mosfellsbær in a massive operation involving around 50 men on Wednesday. Two of them were remanded in custody on Thursday, and the other two were released.
"The origin of yesterday's police operations (...) is part of an investigation into the preparation of a terrorist attack," Karl Steinar Valsson, Iceland's national police commissioner, told reporters.
While the motives are still unknown, the targets would be "various institutions" and "citizens of the state", according to Valsson, possibly including parliament and the police themselves.
Police said they were investigating whether there were links between the men and extremist organisations and were in contact with foreign authorities - with a focus on possible connections with extremist groups in other Nordic countries.
“As far as we know, this is the first time that such an investigation has been launched (in Iceland),” Valsson said.
There are an estimated 106,000 guns held by civilians in Iceland - about one for every three people - and most of the weapons are rifles and shotguns rather than handguns.
Armed crime is rare and the country has strict gun laws: there have only been 52 gun deaths in the last decade that statistics are available, and 50 of them were suicides, according to figures compiled by the Gunpolicy.org database at the University of Sydney.
In February there was an incident in Reykjavik where the gunman also used a 3D printed weapon. In 2013 a man was shot dead after firing on officers, the first time police had shot and killed anyone in Iceland.