Norwegian police are investigating an explosion that occurred on a street in central Oslo, where they later conducted a controlled detonation of a second explosive device discovered at the scene.

Authorities confirmed that a suspect has been taken into custody for questioning but there have been no reports of injuries.

The blast occurred near a university campus, approximately 500 meters from the royal palace and the Israeli embassy. In an unusual move, officials sent an emergency alert to residents’ mobile phones, warning them about the incident.

The second device described by police officer Brian Skotnes as a “military-style” hand grenade, raised concerns. “We’ve apprehended one suspect and are intensively seeking more information as well as other individuals”, Skotnes stated.

He added, “Our hypothesis is that it is criminals who have an agenda against other criminals, but we cannot rule out anything”.

The area is now considered safe, according to police. Reports indicate that a 13-year-old was among those apprehended, although Skotnes did not confirm the suspect’s age.

This incident follows recent reports of drone sightings near airports in Oslo and Copenhagen.