The latest in the events surrounding the purported slaying by Egypt's Islamic State affiliate of Croatian hostage Tomislav Salopek, after an online image was circulated Wednesday showing his beheaded body.

Egypt's foreign minister says authorities are still working to verify the authenticity of a photo circulated by Islamic State group supporters that appears to show the grisly aftermath of the beheading of a Croatian hostage.

Foreign Minister Sameh Shoukry told Al-Arabiya television late Wednesday that the "relevant authorities must first confirm the authenticity of the image that was circulated of the killing of the Croatian citizen."

He added that "these terrorist operations target citizens of different nationalities in a number of countries in the region and the world."

Croatia's President Kolinda Grabar-Kitarovic has expressed her deepest sympathy with the family of Salopek and all his friends but noted that his death has not been confirmed.

She says: "In these moments of deep uncertainty, I am sympathizing with the family, parents and friends of Tomislav Salopek."

Grabar-Kitarovic spoke to reporters in the coastal city of Split.

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 hometown of Vrpolje in Croatia, a family representative and close friend has come out of their home on Wednesday evening to tell media waiting outside that everyone is deeply stricken and in shock over the tragic news.

Stipe Bilokapic says he has been with the family of the Croat hostage since the ordeal started last month with Salopek's abduction in Egypt.

An obviously distraught Bilokapic said of Salopek: "He is my friend. It is shocking."

British Foreign secretary Philip Hammond strongly condemns apparent murder of Croatian hostage by ISIL in Egypt.

“If these reports are true, I condemn in the strongest terms the apparent brutal killing of Croatian national Tomislav Salopek by ISIL in Egypt. My thoughts and condolences are with his family, colleagues and all the Croatian people. Britain will stand by Egypt and Croatia as we continue to oppose this inhuman brand of terrorism.” Philip Hammond said.

The German Foreign Ministry reacted to the killing of Salopek by saying that "this abhorrent act once again shows that the fanatical ideology of ISIS threatens us all."

The statement also says that Germany will do everything possible, with its international partners, "to push ISIS back, not just militarily but above all politically."

ISIS is an alternative acronym for the Islamic State group, which has captured a third of both Syria and Iraq while its affiliates have emerged in countries such as Egypt and Libya. There are also growing numbers of supporters in other countries.

Germany has supplied weapons to Kurdish forces battling the IS group in northern Iraq. A U.S.-led alliance is targeting IS targets in both Syria and Iraq.

In Croatia, residents of Salopek's hometown of Vrpolje expressed utter shock and dismay over his brutal killing by the Islamic State group in Egypt.

One of the townspeople, Slavko Lapac, told The Associated Press that "it is hard to even speak" and that his heart goes out to Salopek's two children and wife.

Lapac, who is in his 50s, says he hopes that "beyond this world, over there, he will find peace and that he will be put among the righteous."

Lapac's wife, Ankica, added that she was shocked at the news coming out of Egypt. "I simply cannot believe this is happening."

Croatian Prime Minister Zoran Milanovic says that authorities in Croatia cannot confirm Salopek's killing with certainty.

He says "we can not 100 percent confirm it is true but what we see looks horrific. A confirmation may not come for several days."

Milanovic, in an address to the nation on Croatian television, also urged people not to expose their children to the gruesome image of Salopek's body posted online and not to distribute it. He says officials "will not stop searching, digging as long as there is a drop of hope."

He also appealed for calm, saying Croatians "have to continue living normally."

Egypt's Al-Azhar institute, the top center of religious learning for Sunni Muslims, has condemned the killing of Salopek, calling it a "demonic act" contrary to all religion.

It also offered condolences to the Croatian people and government and to Salopek's family, calling on Egyptian authorities to go after the culprits and bring them to justice.

The statement also says that under Islamic law, or Shariah, it is forbidden to shed the blood of foreigners, adding that what the "terrorists" did was a betrayal of the Prophet Muhammad and all Muslims.

The chief spokesman for Salopek's employer says "we fear the worst" but could not confirm that he was killed by Islamic State extremists.

Christophe Barnini of France-based seismic survey company CGG told The Associated Press that the company is in touch with Croatian Embassy in Cairo. He said the company cannot determine whether Salopek was killed based only on the image posted Wednesday online.

Barnini says Salopek started working two months ago on a project for a sub-contractor of CGG.

Croatia's foreign ministry said Wednesday they could not confirm Salopek's death. But the country's prime minister, Zoran Milanovic, will be addressing the nation in couple of hours.

Croatian President Kolinda Grabar-Kitarovic said in a statement that she is cancelling all her pre-arranged activities on Wednesday.

France's GCC Ardiseis in Egypt, the subsidiary where Salopek worked as a surveyor, says it has no immediate confirmation of his killing.

A company official, who spoke on condition of anonymity because he was not authorized to speak to reporters, says Salopek was abducted last month on the Oasis Road, west of Cairo.

There has been speculation about where the militants held the Croatian hostage, with some reports focusing on restive north Sinai, the base of the IS affiliate.

But an Egyptian security official says the likelihood of that is small since Salopek was snatched near Cairo at a time when Egyptian forces are at their highest readiness in Sinai and the Red Sea area surrounding the recent inauguration of the extension to the Suez Canal.

He says all security agencies have been working on Salopek's case and that they have no way to confirm the killing. He spoke on condition of anonymity in line with regulations.

*The story was edited by Ahram Online.