Norwegian police said the explosion at the US embassy in Oslo early Sunday caused only minor damage, but the investigation was still in its early stages and they had not ruled out a link to terrorism.
The explosion came as security at US embassies and consulates around the world has been increased as Israel and the US rapidly escalate their bombing campaign against Iran.
Several U.S. diplomatic facilities in Gulf countries that host U.S. troops, including Kuwait and Saudi Arabia, have been targeted by Iran in retaliatory attacks.
It is unclear whether the Oslo explosion is connected to events in the Middle East.
“We have determined that an explosion struck the American embassy,” Oslo police spokesman Michael Delemer told public broadcaster NRK, adding that the explosion occurred at the entrance to the consulate part of the compound.
“In light of the current security situation, it is natural to view this as a targeted attack on the US embassy,” said Frode Larsen, head of the Joint Investigation and Intelligence Division.
“But we are not limited to just that one hypothesis,” Larsen said at a press conference in Oslo on Sunday.
Asked whether the explosion was terrorism-related, Larsen said “one of the theories is that it was terrorism,” but reiterated that police were not “absolutely bound to that.”
The State Department said in a statement Sunday that it was aware of the “incident” at the embassy and was investigating it. The Ministry thanked the Norwegian authorities for their support.
Witnesses reported a large explosion near the embassy compound in western Oslo around 1 a.m.
Police previously said there were no reports of injuries.
Anna Gilbo told CNN she was at home with a friend when she heard the explosion and ran to the window to see a “cloud of smoke” coming from the building.
“While I was watching TV, I heard a loud bang as the whole house shook. My friends and I were worried as there was a search going on for some time after the explosion, but it seems like the threat is over,” she added.
Sebastian Thorstad, an 18-year-old student, recalled seeing a “very thick layer of smoke” on the road as he drove past the embassy at the time of the incident.
“There was some damage to the entrance,” he told Reuters.
The search for the perpetrator continues, but authorities confirmed that no further explosives were found in the area.
CNN has reached out to the embassy as well as Norway’s police and emergency services for comment.
This story has been updated with additional information.
