STOCKHOLM - Sweden's security service said on Thursday that the Iranian government had been using criminal networks within Sweden to carry out violent acts against other states, groups and individuals.

The Security Service said that Iran had targeted the interests of other states in Sweden, and specifically Israel, and had also sought to act against Iranian dissident groups and individuals from the Iranian diaspora.

"The Security Service can now confirm that criminal networks in Sweden are proxies that Iran uses," Daniel Stenling, head of Counter-Intelligence at the service, told a news conference.

There was no immediate response from Iran's foreign ministry to a Reuters request for comment on the Swedish statement.

Sweden's Foreign Minister Tobias Billstrom told news agency TT the Iranian chargé d'affaires in Stockholm would be summoned on Friday.

"It is deeply worrying that a foreign power, in this case Iran, should have used criminal networks to commit or instigate crimes in Sweden," he said.

Sweden has been plagued by gang violence for years and in 2023, 55 people were shot dead and an additional 109 were injured in 363 different shootings. The rest of the Nordic countries had a combined total of six dead shot dead during that period.

Following a suspected shooting incident near Israel's embassy in Stockholm in May, and the discovery of an explosive device outside the same embassy in January, Swedish police increased security around Israeli and Jewish interests within the country.

The Security Service declined to comment on specific attacks but according to a statement obtained by Reuters from an Israeli official, the January incident was carried out by a criminal gang on behalf of Iran.

"Using proxies and exploiting the increasing number of antisemitic incidents against Israel is Iran's way of avoiding leaving its fingerprints on the terrorism it promotes," the statement read.

Stenling said the Security Service saw no reason to doubt the Israeli intelligence but declined to comment on specific details, saying it could compromise ongoing investigations.

The Security Service said the terrorism threat level assessment remained at 4 on a scale of 5, to which it was raised in 2023 after Koran burnings by individuals in Sweden outraged Muslims in several countries and triggered jihadist threats.