Islamic State militants 'behead' Croatian hostage
An online image purports to show the beheading of a Croatian hostage held by Islamic State's (IS) Egyptian affiliate.
It is the first such killing of a foreign captive in Egypt since the extremists set up a branch here.
The killing of the 30-year-old oil and gas sector surveyor likely will rattle companies with expatriate workers in Egypt and cast a cloud over President Abdel-Fattah el-Sissi's attempts to boost international investment to revive the economy, battered by years of turmoil.
The still image, shared by IS sympathisers on social media, appeared to show the body of Tomislav Salopek, a married, father of two, wearing a beige jumpsuit looking like the one he had worn in a previous video. A black flag used by IS and a knife were planted in the sand next to him.
The photo carried a caption in Arabic that said Mr Salopek was killed "for his country's participation in the war against the Islamic State", and after a deadline had passed for the Egyptian government to meet their demands.
The picture also contained an inset of two Egyptian newspaper reports, with one headline declaring Croatia's support of Egypt in its war against terrorism and extremism and another saying Croatia reiterated its support for the Kurdistan region. Croatian troops also were part of the coalition forces in Iraq and they still serve in the Nato-led force in Afghanistan.
The Associated Press could not independently verify the image but it bore markings consistent the filmed hostage demand the group made last week.
In that video, the IS affiliate set an August 7 deadline for Egyptian authorities to free "Muslim women", a term referring to female Islamist prisoners detained in a sweeping government crackdown following the 2013 military ouster of the country's Islamist president.
The extremists' videotaped demand was entitled A Message to the Egyptian Government, and was shot in the style of previous IS propaganda videos.
Mr Salopek, a surveyor working with France's CGG Ardiseis, was abducted in western Cairo last month. The company has an office in the leafy Maadi suburb, where many expats and diplomats live.
Last week, Croatian foreign minister Vesna Pusic met with her Egyptian counterpart in Cairo to press for Mr Salopek's release, while Egyptian foreign minister Sameh Shoukry's office pledged in statement that Egypt would " spare no effort" in the search for him.
IS holds about a third of Iraq and neighbouring Syria in its self-declared "caliphate". In Syria, IS militants have killed foreign journalists and aid workers, starting with American journalist James Foley in August last year.
Mr Foley's taped beheading was followed by the killing of American-Israeli journalist Steven Sotloff, British aid workers David Haines and Alan Henning, American aid worker Peter Kassig, as well as Japanese nationals Haruna Yukawa and Kenji Goto.
Egypt has seen an increase in violence since the ouster of Islamist president Mohammed Morsi, with attacks by suspected Islamic extremists in both the Sinai Peninsula and the mainland focusing primarily on security forces.
Foreign interests also have been targeted increasingly, including the Italian Consulate, which was hit with a car bomb last month. That came just days after another bomb killed Prosecutor General Hisham Barakat in an upscale Cairo neighborhood.
But this is the first time the local Islamic State affiliate purportedly has killed a captive foreigner in Egypt, a major escalation as the country tries to rebuild its crucial tourism industry after years of unrest following the 2011 revolt against autocrat Hosni Mubarak.
Last December, the affiliate claimed responsibility for the killing of an American oil worker with Texas-based energy company Apache. Apache had said that previous August that one of its supervisors had been killed in an apparent carjacking in the Western Desert, part of Egypt's mainland.
Croatia's President Kolinda Grabar-Kitarovic has expressed her deepest sympathy to the family of Salopek but noted that his death has not been confirmed.
She said: "In these moments of deep uncertainty, I am sympathising with the family, parents and friends of Tomislav Salopek."
She also added that she wants to "firmly state that, as long as there is a glimmer of hope, one little crumb of chance that Tomislav is alive, we are continuing to work, continuing the search and continuing efforts to save his life".
In Salopek's home town of Vrpolje, a family representative said everyone was "deeply stricken and in shock" over the news.
Croatian Prime Minister Zoran Milanovic said confirmation of Salopek's death "may not come for several days".
In an address to the nation on Croatian television, he also urged people not to expose their children to the gruesome image of Salopek's body posted online and not to distribute it.
He also appealed for calm.
Egypt's Al-Azhar institute, the top centre of religious learning for Sunni Muslims, has condemned the apparent killing, calling it a "demonic act" contrary to all religion.