The jihadist group ISIS has claimed it executed a Chinese and a Norwegian captive, media reports said Wednesday.  

The graphic pictures published in latest edition of extremist group's English-language magazine Dabiq, shows two bloodied bodies which appeared to be of Chinese Fan Jinghui and Norwegian Ole-Johan Grimsgaard-Oftsad, according to BBC. The magazine, however, did not give more details about the execution. It appeared they have been shot.

The hostages were reportedly executed after their countries and families failed to pay the ransom, which ISIS had demanded for their release. Fan and Grimsgaard-Oftsad were held captive for two months.

Norway's Prime Minister Erna Solberg described the execution a "despicable" and "brutal act." "There is no excuse for the treatment our countryman has been exposed to, neither in religion or ideology. This is a cold-blooded murder," she said in a press conference in Oslo, according to VOA News. 

"We still have to check if the published image is authentic, our experts are doing that now, but so far there is no reason to doubt that it is not authentic," she said, according to DPA. "Norway has some red lines, one is that we never pay ransom. This would put more Norwegians at risk, finance terrorism and violate our international commitments."

On Thursday, China voiced "great shock" over the execution of Fan and vowed to bring his murderers to justice.

"The terrorist organisation has no regard for human decency and the bottom line of morality. They still carried out their barbaric acts of violence. The Chinese government strongly condemns this inhuman atrocity; we must bring these criminals to justice," foreign ministry spokesman Hong Lei said in a statement, according to AFP.

ISIS, also referred to as ISIL or Daesh in Arabic, also claimed responsibility for the recent Paris attacks in it's magazine.

"The Islamic State dispatched its brave knights to wage war in the homelands of the wicked crusaders, leaving Paris and its residents 'shocked and awed,'" Dabiq said, according to Local.