Freelance reporter Martin Schibbye and photographer Johan Persson were found guilty of illegally entering Ethiopia from Somalia and of supporting rebels from the Ogaden National Liberation Front (ONLF).
The prosecution has called for a maximum sentence of 18 years and six months in prison. Their sentences are to be announced on December 27.
“Our position is and continues to be that they were in the country on a journalistic assignment. They must be released as soon as possible in order to be reunited with their families in Sweden,” Reinfeldt said.
“The government considers today’s ruling against the two Swedish journalists Martin Schibbye and Johan Persson in Addis Ababa very serious,” he added.
Reinfeldt said the government was “already making high-level contact with the Ethiopian government in this matter.”
Schibbye and Persson had admitted contact with the outlawed rebel group and to entering Ethiopia illegally, but rejected terrorism charges including accusations they received weapons training.
Last month, charges of participating in terrorism were dropped for lack of evidence.
The two have said they met with the ONLF for professional reasons only, as part of their investigations on the activities of Swedish oil company Lundin Oil.