Islamic State militants stand behind what are said to be Ethiopian Christians along a beach in Wilayat Barqa, in this still image from an undated video made available on a social media website on April 19, 2015. REUTERS/Social Media Website via Reuters TV/File Photo

Islamic State militants stand behind what are said to be Ethiopian Christians along a beach in Wilayat Barqa, in this still image from an undated video made available on a social media website on April 19, 2015. REUTERS/Social Media Website via Reuters TV/File Photo

Islamic State militants stand behind what are said to be Ethiopian Christians along a beach in Wilayat Barqa, in this still image from an undated video made available on a social media website on April 19, 2015. REUTERS/Social Media Website via Reuters TV/File Photo

August 19, 2016 10:22 AM (UTC+8)