March 8 at 1a.m., the U.S. embassy in Oslo, Norway’s capital, was hit by a loud explosion. The blast was identified as a bomb, as eyewitnesses subsequently described a thick smoke tumbling into the streets. Authorities believe the explosion was caused by a device placed at the building’s entrance, close to the consular section, but it was reported to have only caused minor damage and no injuries. The head of the Oslo police investigation unit, Frode Larsen, spoke at a news conference, stating, “It’s natural to see this in the context of the current security situation and that this could be an attack deliberately targeting the U.S. embassy,” suggesting a possible connection to terrorism. Norwegian police are adamant that, although the attack shows signs of terrorism, the investigation is still in the early stages and cannot be assumed. The BBC reports that three brothers have been arrested on suspicion of the bombing. The brothers, all in their 20s, are Norwegian citizens with links to Iraq, but little else is known about them. Police attorney Christian Hatlo stresses that the most important thing is to question the suspects. The Norwegian government contacted officials at the U.S. embassy to convey that this was “an unacceptable act that we take very seriously,” Foreign Minister Espen Barth Eide ​said in his statement.