Islamic State said it had killed a Chinese and Norwegian captive, showing pictures of what appeared to be the dead men under a banner reading "Executed" in the latest edition of its English-language online magazine, Dabiq.

It did not give any details in the magazine, published yesterday, about how, when or where the men were killed.

In a brief statement, China's Foreign Ministry confirmed the man's identify for the first time, naming him as Fan Jinghui, saying he had been "cruelly murdered". It said in September one of its citizens appeared to be in Islamic State captivity.

Beijing had activated an emergency mechanism to try and rescue him, but he was still killed in a "cold-blooded way", the ministry said. It gave no details on how they might have extracted him.

"The Chinese government strongly condemns this savage act devoid of humanity and will certainly bring the criminals to justice," the statement said.

"The Chinese government will resolutely oppose all forms of terrorism and resolutely strike at any violent terrorist criminal activities that defy the bottom lines of human culture," it added, noting Beijing would strengthen anti-terrorism cooperation with the international community.

Chinese President Xi Jinping, visiting Manila for a regional summit, said he strongly condemned the killing.

The militant group had previously identified Fan as a 50-year-old freelance consultant from Beijing.

The state-run Beijing News said Fan was probably a former advertising executive who had once lived in a western suburb of Beijing, but that his company shut down in 2003. It said it had found an advertising firm registered to Fan in western Beijing.

Security officials stood guard outside the low-rise building on Thursday and stopped a Reuters reporter from entering.

"He was just a normal person. I didn't really know him when he lived here but there was nothing special about him," said one resident, who gave her family name as Zhang.

It is unclear why Fan went to the Middle East. Chinese workers in Africa and Pakistan have been held hostage before.

China has repeatedly denounced Islamist militants and urged the world to step up coordination in combating Islamic State, though it has been reluctant to get involved on the ground in Syria and Iraq where the group largely operates.

Chinese officials say the country faces a severe threat from Islamist separatists in its western Xinjiang region, where violence has left hundreds dead over the past three years.

The government says some Uighurs have gone to fight with radical groups in the Middle East.

Western nations have been reluctant to cooperate in China's campaign in Xinjiang, nervous about being implicated in possible human rights abuses. China denies rights abuses in Xinjiang.

Since last week's attacks in Paris, Chinese state media has lambasted Western countries for their "double standards" on terrorism. Influential state-run tabloid the Global Times said the West deserved no sympathy from China.

"The West only recognises its own style of democracy and accepts only the terrorism it suffers," it said in an editorial.