Islamic State Egypt affiliate threaten to kill Croatian hostage in 48 hours - video

CAIRO (Reuters) - An online video, purportedly from Islamic State's Egypt affiliate, showed on Wednesday a Croatian hostage who said the group would kill him in 48 hours if Muslim women in Egyptian jails were not freed.

Croatia's foreign ministry reported on July 24 that a group of armed men had abducted a Croatian citizen in Egypt, identified as T.S.

In the video, titled "A Message to the Egyptian Government" and posted on online forums, a man is seen kneeling and wearing a short-sleeved orange jumpsuit -- clad like previous Western prisoners in Islamic State videos who were later killed.

He identified himself as Tomislav Salopek, 30, from Croatia, who worked for French company CGG.

Reuters could not immediately verify the video's authenticity. If confirmed, it would be the first known video featuring a Western hostage held by Sinai Province, which changed its name from Ansar Bayt al-Maqdis after it pledged allegiance to the Islamic State jihadist movement.

"The Croatian government is doing everything possible to resolve this difficult situation. Taking into account the difficult and sensitive circumstances, we cannot provide any more detailed information at this moment," the foreign ministry said in a statement.

In the video, a masked militant in fatigues stands near Salopek, a knife visible in his hand. The black flag of Islamic State is propped up behind Salopek.

"The soldiers of Islamic State ... Wilayet Sinai, caught me at Wednesday, 22 July, 2015. They want to substitute me for the Muslim women arrested in Egyptian prisons. This matter has to be achieved before 48 hours from now. If not, the soldiers of Wilayet Sinai will kill me," Salopek said, reading from a note against a desert backdrop.

Wilayet Sinai is the Arabic name for Sinai Province.

Ardiseis Egypt, a unit of CGG, which specialises in oil and gas geology, said in a statement that one of its staff was kidnapped on July 22 while travelling to Cairo.

"Ardiseis Egypt acknowledges that he is the hostage appearing on the video released today by the Sinai Province of Islamic State," the company said.

The Egyptian Interior Ministry and Foreign Ministry did not comment on the video. Egypt's military spokesman and the presidency could not be reached for comment.

The timing of the video coincided with Egypt's preparations to inaugurate the New Suez Canal, a megaproject that is the centrepiece of President Abdel Fattah al-Sisi's plans to revitalise the country's economy.

Sinai Province is the most active insurgent group in the Sinai Peninsula, the epicentre of an insurgency in Egypt and part of which flanks the Suez Canal.

Hundreds of soldiers and police have been killed in militant attacks since the army ousted Islamist President Mohamed Mursi after mass protests against his rule in 2013.

(Additional reporting by Andrew Callus and Geert De Clercq in Paris and Igor Ilic in Zagreb; Reporting by Cairo bureau; Writing by Yara Bayoumy; Editing by Ralph Boulton)