An Ethiopian court has convicted two Swedish journalists of supporting terrorism. Ethiopian troops captured Johan Persson and Martin Schibbye six months ago during a clash with rebels in the East African state's Somali region. The court ruled it was "very unlikely" that they had entered Ethiopia illegally only to gather news. Swedish Prime Minister Fredrik Reinfeldt said they were innocent and should be freed. Judge Shemsu Sirgaga said the Ogaden National Liberation Front (ONLF) rebel group - which Ethiopia regards as a a terrorist organisation - had arranged the men's journey from London to Ethiopia, with stop-overs in Kenya and Somalia, the AFP news agency reports. They entered Ethiopia illegally under the pretext of investigating the impact of potential oil discoveries, he said. 'Expressionless' "Instead they accompanied the ONLF into the country and were caught alongside the rebels. This contradicts their claims," the judge said. "Guilty as charged, period, unanimous vote." Both reporters appeared expressionless at the verdict and it was not clear whether they understood the judge since they had no translator, AFP reports. Mr Reinfledt said Sweden viewed the convictions in a very serious light and was already making high-level contact with the Ethiopian government to secure their release. "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," Mr Reinfeldt said. During their trial, the journalists admitted entering Ethiopia illegally with the ONLF but denied terrorism charges. The prosecution has asked for Persson and Schibbyethem to be sentenced to 18 years and six months in prison. The freelance journalists were on an assignment for Filter magazine when they were arrested, the Reuters news agency reports. Its Swedish-based editor-in-chief Mattias Goransson said they were "political prisoners", it reports. "When the judge read out the grounds it sounded positive, he had virtually nothing against them," Mr Goransson is quoted as saying. "Everything he said was speaking for an acquittal, and then he found them guilty anyway. This indicates they are political prisoners and nothing else." Human rights group Amnesty International said they had been prosecuted for doing "legitimate work". "The overly broad provisions of the Anti-Terrorism Proclamation allow the authorities to criminalize the exercise of freedom of expression," said Claire Beston, the group's Ethiopia researcher, the AP news agency reports. Since the 1970s, the ONLF has been fighting for the rights of Somali-speaking Ethiopians, who they say have been marginalised by the government in Addis Ababa. One ONLF faction signed a peace deal with the government last year, but another splinter group has continued to fight the army. Human rights groups have repeatedly accused the government of widespread atrocities in the Somali-speaking region, where journalists need permission to travel.