Norwegian police have sealed off a large area of the Gronland neighborhood in downtown Oslo after a suspected explosive device was discovered late Saturday. Police said that one person has been detained in connection with the incident.

The detained individual is being questioned as a suspect, Oslo police service said on its official Twitter page.

Eyewitnesses report that a large number of police cars and ambulances have been called to the area. The suspicious-looking item was found near a bridge on Grønlandsleiret, one of the Norwegian capital’s main streets, police spokesman Svein Arild Jørundland told VG, adding that a bomb squad has been dispatched to the scene.