Reuters, Cairo : A video purportedly prepared by the self-styled Islamic State (IS) and posted on social media sites on Sunday appeared to show militants shooting and beheading about 30 Ethiopian Christians in Libya.The authenticity of the video could not be verified but the killings resembled past violence carried out by IS, an ultra-extremist group which has expanded its reach from strongholds in Iraq and Syria to conflict-ridden Libya.The video, in which militants call Christians “crusaders who are out to kill Muslims”, showed about 15 men being beheaded on a beach and a second group of the same size being shot in the head in another area.Both groups of men are referred to in a subtitle as “worshippers of the cross belonging to the hostile Ethiopian church”. Libyan officials were not immediately available for comment.Ethiopia said it had not been able to verify whether the people shown in the video were its citizens. “Nonetheless, the Ethiopian government condemns the atrocious act,” government spokesman Redwan Hussein said. He said Ethiopia, which does not have an embassy in Libya, would help repatriate Ethiopians if they wanted to leave Libya.Militants professing loyalty to IS have claimed several high-profile attacks on foreigners in Libya this year, including an assault on the Corinthia Hotel in Tripoli and the beheading of 21 Egyptian Christians in February. The killing of the Egyptians prompted Egyptian President Abdel Fattah al-Sisi to order air strikes on IS targets in Libya.In the latest video, a man dressed in black clutching a pistol stood behind some of the victims. “The Muslim blood shed under the hands of your religions is not cheap,” he says, looking at the camera.”To the nation of the cross: We are now back again.” The video concludes with a warning that Christians will not be safe unless they embrace Islam or pay protection money.Meanwhile, the United States condemned the “brutal mass murder” of 30 Ethiopian Christians in Libya following a video released by Islamic State militants purportedly showing their execution. The 29-minute IS video appears to show militants holding two groups of captives, described in text captions as “followers of the cross from the enemy Ethiopian Church”.National Security Council spokeswoman Bernadette Meehan decried the killings and called for stability in Libya, which has been mired in political chaos and unrest since the 2011 uprising that toppled former strongman Moamer Kadhafi. “The United States condemns in the strongest terms the brutal mass murder purportedly of Ethiopian Christians by ISIL-affiliated terrorists in Libya,” she said, using another name for IS. “This atrocity once again underscores the urgent need for a political resolution to the conflict in Libya to empower a unified Libyan rejection of terrorist groups.” Ethiopia said its embassy in Egypt was trying to verify the video to ascertain if those murdered were indeed its nationals. “We strongly condemn such atrocities, whether they are Ethiopians or not,” Communications Minister Redwan Hussein told the news agency.