The bodies were discovered in an outhouse attached to a larger residential house. Police have called in forensic experts to ascertain whether there might by any suspicion of criminal intent.
“We are in the process of identifying the bodies and are trying to get in touch with their families,” said police spokesman Björn Engström.
It is not yet know whether anybody was living in the 25 square metre building burned down in the fire.
A fire in Falun on Sunday night also claimed two lives.
Police and emergy services have not found the cause of the blaze, which destroyed a four-storey apartment building and left twelve people needing hospital treatment.