Amnesty International has urged the UN Security Council to refer the situation in Syria to the International Criminal Court and to demand "prompt and unhindered" access to the country by an independent inquiry, as well as human rights groups and journalists.
The human rights organisation said Syrian government forces and armed opposition groups in Aleppo were committing "grave human rights abuses and serious violations of international humanitarian law, many of which amount to war crimes".
"In some cases, the actions of the Syrian government have amounted to crimes against humanity," Amnesty said in a report, Death Everywhere – War Crimes and Human Rights Abuses in Aleppo, Syria.
Violations committed by the government and many armed opposition groups in Aleppo were in defiance of UN Security Council Resolution 2139, adopted more than a year ago.
Amnesty said evidence strongly suggested that government forces and many armed opposition groups were “indiscriminately using imprecise explosive weapons such as barrel bombs and mortars on a systematic basis”.
Barrel bomb attacks killed at least 3,124 civilians and 35 fighters in Aleppo governorate from January 2014 to March 2015, the report said.
Systematic attack
“The government’s aerial campaign in Aleppo appears to have deliberately targeted civilians and civilian objects and forms part of a systematic, as well as widespread, attack against the civilian population throughout Syria, a campaign that is also marked by the torture, murder and enforced disappearance of thousands of civilians in Aleppo and across Syria,” the report said.
As the evidence pointed to these violations being committed in furtherance of a state policy, Amnesty’s assessment was that they amounted to crimes against humanity. It was also “gravely concerned” about reports of sexual and gender-based violence in Aleppo.
Many opposition groups had engaged in abductions and hostage-taking, as well as in the torture and other mistreatment of prisoners in Aleppo from January 2014 to March 2015, the report also concluded.
Amnesty said residents of both opposition-held and government-held areas had been subjected to extremely poor living conditions, including shortages in basic services and necessities such as food and medicine.
It noted the Syrian government had “failed to acknowledge that its aerial bombardment campaign in Aleppo had resulted in a single civilian casualty” and that it had insisted its air attacks had targeted only “terrorists”.
Amnesty called on all parties in the conflict to end deliberate attacks on civilians and civilian objects such as hospitals and schools; to end the indiscriminate use of explosive weapons such as barrel bombs and mortars in populated areas; to end arbitrary arrests, enforced disappearances, abduction and torture and other ill treatment and to allow unimpeded humanitarian access to the UN and its partners.
Separately, the United Nations said on Tuesday it had launched its third major push in as many years to find common ground between the parties in Syria, and for the first time said it hoped the armed opposition groups might come to Geneva.
A year after the failure of UN-mediated talks between the Syrian government and opposition representatives, UN Syria envoy Staffan de Mistura aims to hear the views of more than 40 groups, one by one, over the next six to eight weeks, and possibly longer.
Mr de Mistura, who is the third such special envoy to Syria, began the consultations on Tuesday by meeting with Hussam Edin Aala, Syria’s ambassador to the UN, in Geneva.