Police said that as of Tuesday an area in central Stockholm, known as "Diplomatstaden" ("The Diplomat City"), would be designated a "security zone", and this would remain in force until April 7.

"The ongoing armed conflict in the Middle East... is not limited to that geographical area alone. The conflict has had repercussions in other regions as well, where Israeli, Jewish, and American interests are present," police said in a statement noting that both the Israeli and US embassies were in the area.

Designating an area a "security zone" means police will be able to search people and vehicles without a formal suspicion of a crime.

"In practice, this means that the police will have a higher presence than usual and carry out more preventive controls," police said in a statement.

Sweden gave police the power to create "security zones" in 2024 in response to a surge in violence linked to criminal networks.

Swedish police had already stepped up security around potential targets since early March.

The Swedish Security Service (Sapo) has previously accused Iran in particular of recruiting members of Swedish criminal gangs to commit "acts of violence" against Israeli and other interests in Sweden -- a claim Iran denied.