Turks reacted angrily Friday on social media to a video released by the Islamic State group purportedly showing two captured Turkish soldiers being burned alive, while awaiting an official reaction from the government.
The 19-minute video, showing two uniformed men being hauled from a cage before being bound and torched, was posted on jihadist websites and supposedly shot in the IS-declared "Aleppo Province" in northern Syria.
The video, which sparked outrage in Turkey, came as the Turkish military was suffering its worst losses in its fight against jihadists in northern Syria, where nearly 90 civilians have been killed since Thursday in Turkish raids, according to the Syrian Observatory for Human Rights.
Speaking in Turkish, the killer of the two men criticises Turkish President Recep Tayyip Erdogan and calls for "destruction to be sowed" in Turkey.
By mid-Friday, the Turkish authorities had not yet reacted but Erdogan and Prime Minister Binali Yildirim were due to speak later in the day in Izmir in western Turkey.
Despite reported difficulty in accessing some sites, especially Twitter and Facebook, internet users were widely discussing the brutal video, with one saying "it's a nightmare".
Twitter, Facebook and YouTube were difficult to access in Turkey on Friday, according to Turkey Blocks, a website specialising in tracking internet censorship.
The traumatic images added to the pain suffered by Turks, who have had to deal with several attacks -- including several claimed by IS jihadists -- a bloody but failed coup and, this week, the assassination of Russia's ambassador in Ankara.
According to pro-government news agency Anadolu, Turkish police arrested 31 people suspected of links with IS on Friday and were hunting for 10 more. It was not clear if the arrests were linked to the video.
The shocking images recall the killing of Maaz al-Kassasbeh, a Jordanian fighter pilot, who was captured by the jihadists when his plane went down in Syria in December 2014, and was later burned alive in a cage.
Before being burned, the two victims gave their names in Turkish as Fethi Sahin, born in Konya in central Turkey and Sefter Tas, a 21-year-old serving in Kilis in the southeast.
According to Turkish media, a soldier by the name of Sefter Tas was kidnapped by IS on September 1, 2015, but Ankara never confirmed the capture.
The Turkish army however did confirm last month it had lost contact with two of its troops in Syria and the IS-linked propaganda agency Amaq had claimed their capture by the jihadists. Again, Turkish authorities did not confirm the alleged kidnapping.
The video came shortly after 16 Turkish soldiers were killed by IS fighters in Ankara's biggest loss so far in its unprecedented incursion into Syria.
They were killed in a succession of attacks around the Syrian town of Al-Bab on Wednesday that included three suicide car bombings.
The video was also published just hours after Erdogan vowed no let-up in the ongoing campaign.
"Yes, maybe we will have to lay martyrs to rest," he said in a speech in Ankara.
"But we are determined to preserve their memory and protect what they left us and continue this struggle."
With Turkish involvement in the battle intensifying, the Syrian Observatory said at least 88 civilians had been killed in 24 hours of Turkish air strikes on an Islamic State group bastion in northern Syria.
At least 35 Turkish soldiers have been killed since the August 24 start of Turkey's campaign in Syria codenamed Operation Euphrates Shield.