Police in Oslo are investigating a human-caused explosion at the US Embassy as a potential act of terrorism after a backpack bomb detonated Sunday.Justice Minister Astri Aas-Hansen and Foreign Minister Espen Barth Eide held talks with Eric Meyer to coordinate security following the consular section blast.Investigators recovered forensic evidence including shattered glass and black marks at the scene while drones and canine units searched for suspects.The incident occurred while intelligence agencies warned of threats from the Iranian Revolutionary Guard Corps and Iranian-backed groups against missions.