The United Nations adviser on the prevention of genocide, Adama Dieng , has expressed deep concern at the deteriorating situation of civilians trapped in Syrias Raqqa. “I am deeply disturbed by reports coming out of Raqqa of the horrendous situation faced by civilians caught up in the offensive to retake the city from ISIS,” said Dieng in a statement released by the Office of the Spokesperson for the UN Secretary-General. International counter-ISIS coalition forces and the Syrian Democratic Forces (SDF) are carrying out airstrikes, and ISIS, which still controls Raqqa, is reportedly using civilians as human shields, he added. According to the statement, up to 25,000 civilians remain trapped in Raqqa. ISIS militants are reportedly killing those who try to escape, and coalition forces are targeting boats on the Euphrates river, which had been one of the remaining escape routes for civilians. Civilians in south of the Euphrates river are reportedly facing indiscriminate attacks by Syrian regime forces and their allies during military operations to retake the area, it said. “The legitimate aim of retaking Raqqa must not be achieved at such a high cost to civilians,” said the Special Advisor, urging all parties to adhere to their obligations under international human rights and international humanitarian law, including the protection of civilians. Reiterating calls for a humanitarian pause to spare civilian lives, Dieng warned that as the offensive to retake Raqqa reaches its final stages, the fighting is likely to intensify and increase the risks faced by civilians still trapped in the city.