(12 Aug 2014) The New-York based Human Rights Watch (HRW) called Tuesday for an international commission of inquiry into mass killings by Egyptian security forces last summer, saying they likely amount to crimes against humanity. Based on a year-long investigation into the incidents that followed the ouster of Islamist President Mohammed Morsi on July 3, 2013, HRW called specifically for an inquiry into the role of the country's current President Abdel-Fattah el-Sissi, and at least 10 senior military and security chiefs in the killing of 1,150 protesters in the span of six weeks. The 188-page report said it found that authorities had used excessive and deliberate force against protesters on political grounds in successive attacks on their gatherings. The worst incident of mass killings occurred on August 14, when authorities opened fire on a massive pro-Morsi sit-in at Cairo's Rabaah al-Adawiyah square. HRW said the day's death toll there was at least 817 and likely as high as 1,000, higher than the toll of 624 documented earlier by the state's human rights body. "Human Rights Watch said today that in 2013 the Egyptian security forces have deliberately targeted and killed a large number of protestors in what has been known as the Rabaah al-Adawiyah sit-ins in Cairo. Human Rights watch also said that those responsible for these crimes against humanity- what could be crimes against humanity should be held accountable by an investigation committee assigned by the UN," Fadi al-Qadi, HRW advocacy and communication director for the Middle East said on Tuesday. "In those events the Egyptian security forces have carried out, according to a human rights watch investigation, a deliberate, systematic killing of protestors using live ammunition without giving those inside the rallies and protests any effective warning. Those accountable, those who are responsible for these perpetrated and systematic killings should be held accountable," he added. HRW called it the "world's largest killings of demonstrators in a single day in recent history." The Egyptian government had said the sit-ins had constituted a disruption of public order and security and accused the encampments of harbouring "terrorists." However, the HRW report said the dispersals of the large sit-in were not isolated developments, but rather "part of a systematic campaign by the Egyptian government to violently disperse dissent." Find out more about AP Archive: http://www.aparchive.com/HowWeWork Twitter: / ap_archive Facebook: / aparchives Instagram: / apnews You can license this story through AP Archive: http://www.aparchive.com/metadata/you...