An early morning blast at US embassy in Oslo has sparked a sweeping investigation by Norwegian authorities, who say terrorism remains one of several possible explanations for the explosion that rattled the diplomatic compound.

The explosion occurred in the Norwegian capital during the early hours of Sunday, leaving minor damage to the embassy building but causing no injuries, according to officials.

Police confirmed they are examining multiple theories surrounding the incident, including the possibility that the explosion was deliberate.

“One of the hypotheses is that it is an act of terrorism, but we are not completely locked into it,” Frode Larsen, head of the police joint investigation and intelligence unit, told Norway’s public broadcaster NRK.

Emergency Response Mobilized Overnight

Police Deploy Large Resources to Embassy Area

Authorities said a large-scale emergency response was launched shortly after the blast occurred.

Police dispatched “large resources” to the area surrounding the U.S. diplomatic mission at approximately 01:00 local time Sunday (00:00 GMT).

Officers quickly secured the site and opened communication with embassy officials.

“The police are in dialogue with the embassy and no injuries have been reported,” Norwegian authorities said in an earlier statement.

The U.S. State Department also acknowledged the incident.

A spokesperson confirmed that officials are aware of the explosion at the embassy in Oslo and are currently reviewing the situation.

Explosion Occurred Near Public Entrance

Damage Reported But No Casualties

According to Michael Dellemyr, the officer leading the police response, the explosion occurred near the public entrance of the embassy building.

The embassy complex is located in the Morgedalsvegen district, about 7 kilometers (4 miles) outside central Oslo.

Police quickly began combing the surrounding neighborhood, searching for clues that might explain the blast.

Authorities also issued a public appeal for information, urging anyone who may have seen or heard unusual activity overnight to contact investigators.

Images Reveal Impact of the Blast

Photographs shared on social media after the incident offered a glimpse of the damage.

The images showed shattered glass scattered across snow-covered ground outside the embassy’s consular entrance. Cracks could be seen splintering through a glass door, while dark scorch-like marks appeared across sections of tiled flooring.

Although the structural damage appeared limited, the scene carried the unsettling signature of a sudden shockwave — like a thunderclap trapped within the quiet stillness of a winter night.

Officials Condemn Incident

Norwegian officials quickly condemned the attack and reaffirmed their commitment to protecting diplomatic facilities.

Foreign Minister Espen Barth Eide described the incident as “unacceptable” and emphasized the importance of safeguarding embassies and diplomatic missions.

“The security of diplomatic missions is very important to us,” Eide said.

He added that he had personally contacted Eric Meyer, the U.S. embassy’s chargé d’affaires, following the explosion to discuss the situation.

Investigation Remains Open

Despite early speculation, investigators caution that the cause of the explosion remains uncertain.

Larsen later reiterated that police must remain open to multiple explanations as the investigation unfolds.

“We have to be open to the possibility that there may be other causes behind what has happened,” he told NRK.

For now, the blast at US embassy in Oslo remains under intense scrutiny as forensic teams examine the scene and intelligence officials analyze potential threats.

What began as a quiet night in Norway’s capital has become a high-stakes investigation — one that authorities hope will soon reveal whether the explosion was an isolated incident or something far more deliberate.