The identity of a man purportedly killed execution-style in an Internet video released by Islamic State militants this week appears to be corroborated by information posted on social-networking sites and interviews with residents in southern Kazakhstan.
A social-media user told RFE/RL's Kazakh Service this week that a man resembling one of two purported "Russian agents" allegedly shot dead in the video was her husband, while a possible former classmate says he was called in for questioning by Kazakh security officers.
The video, released January 13, appears to show a child militant shooting two captives in the back of the head after they are filmed saying that they infiltrated IS fighters in Syria on behalf of Russia's Federal Security Service (FSB).
A photograph of an individual resembling one of the men in the video, who identifies himself as 38-year-old Zhanbolat Mamaev from the Zhambyl region in southeastern Kazakhstan, was posted last year on the popular Russian social networking site Vkontakte by a user with the profile name "Amina Mamaeva."
A person using that account told RFE/RL's Kazakh Service that she was the wife of the man in the photograph on her Vkontakte page, that his name is Zhanbolat Mamaev, and that they have three children.
"He wasn't an FSB agent. He worked as a taxi driver in the city," the Vkontakte user, who indicated that she lives in the city of Karachaevsk in Russia's North Caucasus republic of Karachaevo-Cherkessia, wrote in an online chat. "He was a true husband and father."
The user claimed to have seen the video in which "Zhanbolat Mamaev is killed" but declined to give further comment or be interviewed by telephone.
In a follow-up chat on January 14, the user denied knowing the man in the IS video. The photograph of the individual resembling the man -- part of a collage that included images of three children -- was removed from the user's Vkontakte page within minutes after chatting with RFE/RL.
Other photos resembling the man who claims in the IS video to be Zhanbolat Mamaev can be found elsewhere on social media, including on the Russian networking site Odnoklassniki.
The Odnoklassniki profile where one such image appears gives the name "Zhanbolat Mamaev" and lists the same age indicated by the man in the video: 38. It also lists Merke -- the name of both a town and district in the Zhambyl region -- as the user's location. The profile also lists Karachaevsk as the user's location.
Meanwhile, a Vkontakte page featuring a photo of what appears to be the same man was created as early as October 2013 under the name "Seifullakh Mamaev." The profile lists Merke as the user's location and appears to have last been accessed on October 8.
A January 14 photo on the VKontakte profile of "Seifullah Mamaev"
The profile also indicates that the user attended School No. 48 in the village of Oital in the Merke district.
The school's deputy director, Bakhyt Alipbaeva, told RFE/RL's Kazakh Service that a boy named Zhanbolat Mamaev who was born in 1976 indeed attended the school, beginning in the first grade and ending in the ninth grade in 1992.
"He received his certificate of post-primary education in our school," Alipbaeva told RFE/RL's Kazakh Service, noting that he had less-than-stellar grades in several subjects.
A man identifying himself as Mukhametjan Muzarapov said in an interview with RFE/RL's Kazakh Service the he attended the school with Mamaev but that his classmate left the area with his family around 20 years ago.
"We haven't heard anything about them since then," Muzarapov said. "I don't know where they moved to or whether they still have relatives here. He lived in the village of Bolshevik and studied at our school. His father was a Kazakh and his mother an [ethnic] Karachay."
Muzarapov said he was contacted by Kazakhstan's National Security Committee (KNB) after the IS video began circulating on the Internet this week.
"They want to ask whether I know him or not," Muzarapov said.
Neither Muzarapov nor Alipbaev had seen the video, and thus could not confirm that the Zhanbolat Mamaev who attended the school was the same person shown in the IS video.
Little has emerged about the second alleged victim shown in the video, who identified himself as Sergei Ashimov and also said he worked for the FSB.
On January 15, Kommersant reported that Ashimov was born in 1994 in Karaganda, Kazakhstan, where he was raised as an orphan and attended a boarding school. The Russian daily reported that he was trained to be a driver and moved to Kazan, the capital of Russia's Tatarstan Republic, less than a decade ago and received Russian citizenship.
He initially wanted to study at Moscow State University, and considered pursuing an acting career or enrolling in the FSB's higher school. Eventually he became an entrepreneur selling perfumes before closing his business and taking work as a driver.
Kommersant reports that Ashimov described himself as a "Russian convert to Islam," went on pilgrimage to Mecca and later the Hajj. The Russian daily cites a social-networking site as saying that he received a theological education at the Russian Islamic Institute in Kazan, although it notes that it could not confirm this information.
Russian diplomats in Syria said on January 14 that they are examining circumstances surrounding the release of the IS video and the possibility that the two men allegedly killed were Russian citizens.
"So far, we do not have information to confirm that any of those shown [in a video] is a Russian citizen. The embassy is looking into the information suggesting that this could have been an execution of Russian citizens, particularly members of Russian special services,"Oleg Samochkin, a spokesman for the Russian embassy in Syria, was quoted by Interfax as saying.
In a press release issued on January 15, Kazakhstan's National Security Committee said that "it has been reliably confirmed that the persons shown in this video are not citizens of the Republicof Kazakhstan."