A so-called security zone in parts of Diplomatstaden in Östermalm in Stockholm has been in effect since March 23.
Within the zone, police are allowed to search people and vehicles even without concrete suspicion of a crime.
The decision was initially valid until Tuesday but has now been extended to April 21.
According to the police, the reason is a continued risk of serious crime due to the war in Iran.
"Considering previous incidents and the threat posed to these interests, there is a significant risk of serious crime including shootings and explosions in the area," the police wrote on their website.
