A total of seven cases have been reported in and around Stockholm, including in Vallentuna, Solna and Haninge. The incidents are classified as, among other things, attempted gross fraud and fraud.
According to the police, the victims are in their 80s and 90s, and in several cases the suspected crimes are said to have taken place in their homes.
It is unclear whether the incidents are connected.
Police urge the public never to call phone numbers listed in unexpected text messages.
"If you want to get in touch with a company or authority, use established contact channels that you already have or find yourself, for example on their websites," the authority writes.
