Isis: What we know about jihadist group's hostages Ole Johan Grimsgaard-Ofstad and Fan Jinghui

On the final pages of the latest edition of Islamic State's (Isis) propaganda magazine, Dabiq, are chilling images. Two men wearing yellow jumpsuits are pictured looking at the camera. 'For sale' reads the message.

Under each picture is the following message: "To whom it may concern of the crusaders, pagans and their allies as well as what are referred to as human "rights" organisations. This prisoner was abandoned by his government which did not do its utmost to purchase his freedom."

Under the photograph of each man is a number for encrypted communication app Telegram for "whoever would like to pay the ransom for his release and transfer". The men are identified as Norwegian Ole Johan Grimsgaard-Ofstad, 48, from Oslo, and Fan Jinghui, 50, from Beijing with the men's occupations, place of birth and home address listed.

Norwegian Prime Minister Erna Solberg confirmed one of the men was a Norwegian hostage in his forties, who was kidnapped in Syria at the end of January. She said evidence indicated IS kidnapped the man and had demanded "significant amounts of ransom money".

"We cannot give in and won't give into pressure from terrorists and criminals. Norway does not pay ransom," she said. Chinese authorities did not confirm the identity or nationality of the purported hostage.

"We have noticed it [the advert] and we are working on the case", foreign ministry Hong Lei told reporters. Previously, IS has kidnapped a series of foreign hostages, including UK, US, Japanese and Croatian citizens.

Ole Johan Grimsgaard-Ofstad

On 24 January, Grimsgaard-Ofstad posted a status update on his Facebook page: "I am in Idlib, Syria. Going to Hama tomorrow. I finally made it." Previously he posted pictures of a Turkish border crossing, and the Turkish town of Reyhanli, which is 23 miles north of Idlib.

Idlib has been fought over by Syrian government forces and rebel groups for two years. On 9 September, the last remaining military base in the city was seized by jihadist group Jabhat al Nusra. Norwegian media reports that Grimsgaard-Ofstad was passed between several groups before ending up in the hands of Isis.

A family member told Norway's Telemarksavisa the picture published by IS was of Grimsgaard-Ofstad. On his social media pages, he says he is a student at Norwegian University of Science and Technology. The ransom page lists his occupation as Candidate for Masters in Political Science.

A former acquaintance of Grimsgaard-Ofstad told Norway's TV2 that he had been involved in anti-immigrant activism in the 1990s. In Facebook postings, Grimsgaard-Ofstad post articles critical of satirical magazine Charlie Hebdo, which published portraits of the Prophet Mohammed, as well as articles on the Syrian civil war, and on Russian far right ideologue Alexander Dugin.

Fan Jinghui

Much less is known about Fan Jinghui, who is described in the ransom poster as a freelance consultant. The Chinese foreign ministry would not confirm the identity of the man offered for ransom, and the Chinese embassy in Baghdad told China's Legal Evening News that it had not received any information about the kidnapping of a Chinese hostage by IS.