Explosion in Oslo prompts police to warn of more explosives, residents urged to stay away from windows

An explosion was reported in central Oslo on Pilestredet, triggering a rapid police response and a limited evacuation as authorities warned residents to stay away from windows while investigators assess the scene.

Oslo Police operations manager Øyvind Hammervold told TV2 that investigators are working on the basis of a main theory that a hand grenade was planted. Pictures from the scene show armed police have shut off the road and firefighters are on standby as responders secure the area and begin a careful sweep for any additional devices.

Emergency services were dispatched to the central district amid reports of a blast, and officials said there could still be unexploded devices at the site. Police cautioned that the risk remains until a full search has been completed, and urged the public to avoid the area and follow official instructions.

Authorities had not immediately confirmed casualties or a potential motive. They emphasized that it was too early to determine responsibility and that the investigation would require time and careful forensic work. The blast location, Pilestredet, is in a busy part of the city, complicating response logistics and safety measures for bystanders.

In the hours after the blast, police and emergency services reiterated the need for residents in nearby buildings to remain indoors, keep away from windows, and await updates from official channels. The incident was described as breaking news, with authorities promising further information as it becomes available. While investigators pursue multiple lines of inquiry, officials stressed that no conclusions should be drawn until a thorough assessment is completed, and that security measures in Oslo would remain heightened as a precaution.