[10][11][12][13] The U.N. commission investigating human rights abuses in Syria confirms at least nine intentional mass killings in the period 2012 to mid-July 2013, identifying the perpetrator as the Syrian government and its supporters in eight cases, and the opposition in one.

The report stated that pro-Assad forces "continued to perpetrate massacres and conduct widespread attacks on civilians, systematically committing murder, torture, rape and enforced disappearance amounting to crimes against humanity".

[21] According to a UN report published in August 2014, Assad regime was perpetrating indiscriminate bombing of civilian populations, engaging in chemical warfare, torture, forced disapperances, and extrajudicial murder of detainees.

[58] In a 23 October 2012 statement, Human Rights Watch said that Syrian military denials notwithstanding, HRW had "evidence of ongoing cluster bomb attacks" by Syria's air force.

HRW analysis of satellite imagery in 2014 showed that in the subsequent two years, the Syrian authorities had demolished a total of at least 145 hectares of mostly residential buildings in seven neighbourhoods in Hama and Damascus.

"[63] The Syrian government reportedly used "barrel bombs" to attack civilian populations in rebel held territories in defiance of United Nations Security Council Resolution 2139 passed on 22 February 2014.

[64] The bombs are "cheaply made, locally produced, and typically constructed from large oil drums, gas cylinders, and water tanks, filled with high explosives and scrap metal to enhance fragmentation, and then dropped from helicopters".

[64] According to a UN report published in August 2014: "Government forces continued to perpetrate massacres and conduct widespread attacks on civilians, systematically committing murder, torture, rape and enforced disappearance amounting to crimes against humanity.

Government forces have committed gross violations of human rights and the war crimes of murder, hostage-taking, torture, rape and sexual violence, recruiting and using children in hostilities and targeting civilians.

[64] According to a UN investigation, in September 2016 the Syrian air force dropped barrel bombs from helicopters on a United Nations humanitarian aid convoy at Urum al-Kubra headed to Aleppo.

[73][74] On 30 January 2014, Human Rights Watch released a report detailing, between June 2012 and July 2013, government forces razing to the ground seven anti-government districts in the cities of Damascus and Hama, equating to an area the size of 200 football fields.

According to Physicians for Human Rights, the Syrian government "responded to popular protests with months of sustained and extreme violence and intimidation, and an all-out assault on the country's medical system.

"The New Yorker magazine cites the group stating that in the five years since the war started "the Syrian government has assassinated, bombed, and tortured to death almost seven hundred medical personnel.

"[103] The 2019–2020 UN HRC report for the first time directly accused Russian Air Force of "indiscriminate attacks in civilian areas" in connection to bombing of refugee shelter in Haas and market place in Ma’arrat al-Nu’man in summer 2019, and described them as "amounting to the war crime".

"[121][122] Navi Pillay, the United Nations High Commissioner for Human Rights, stated in March 2012 that Syrian military forces and Ba'athist paramilitaries were systemically abducting, detaining and torturing children.

Suggesting that the UN Security Council should turn Bashar al-Assad over for prosecution in the International Criminal Court (ICC), Navi Pillay said: "They've gone for the children - for whatever purposes - in large numbers.

[123][124] In 2012, the United Nations-sponsored "Independent International Commission of Inquiry on the Syrian Arab Republic" reported that rebels had committed war crimes, but that they "did not reach the gravity, frequency and scale" of those by state forces.

[141] In 2014, the UN Commission of Inquiry reported that since July 2013 Jabhat Al-Nusra, at times in coordination with other armed groups, carried out a series of killings of Kurdish civilians in Al Youssoufiyah, Qamishli and Al-Asadia (Al-Hasakah).

[145] On 20 March 2012, Human Rights Watch issued an open letter to the opposition (including the FSA), accusing them of carrying out kidnappings, torture and executions, and calling on them to halt these unlawful practices.

[185] In April 2016, SDF officials alleged that some of their wounded fighters were displaying signs of chemical weapon injuries after being shelled by the Syrian opposition militia Jaysh al-Islam.

[205] According to the Syrian Observatory for Human Rights, the 16th Division's Badr Martyrs Brigade, led by Khaled Hayani, was responsible for the deaths of more than 203 civilians, including 42 children, at least 25 women, and 136 men, with more than 900 wounded, 175 of them seriously, in the city of Aleppo between July and December 2014 with hell cannons and other mortars, in addition to improvised explosive devices.

[209] The following day, in an apparent reaction to Del Ponte's comments, the commission issued a press release clarifying that it "has not reached conclusive findings as to the use of chemical weapons in Syria by any parties in the conflict".

[220] In June 2015 the Turkish government and Amnesty International reported that the YPG was carrying out an ethnic cleansing of non-Kurdish populations as part of a plan to join the Jazira and Euphrates regions into a single territory.

[222] On 15 March 2017, a video surfaced that showed members of a Syrian Democratic Forces component militia, the Northern Sun Battalion, torturing an IS fighter, who had been captured while planting mines.

[234][235] According to AP, "Jihadi groups are believed responsible for most kidnappings" from Summer 2013 to November, but "government-backed militias, criminal gangs and rebels affiliated with the Western-backed Free Syrian Army" also have been involved with various motives.

[234] The Atlantic blamed the kidnappings on chaos and extremist armed opposition groups motivated by a "combination" of criminality and jihadism, and credited the abductions with "bringing on-the-ground coverage" of the civil war to a halt.

[259][260][261] A 2020 report by UN Human Rights Council for the first time directly laid responsibility on Russian Air Force of indiscriminate attacks on civilian targets "amounting to a war crime".

[262] Abdullah had reportedly moved to Sweden three years previously, and was identified by other Syrian refugees after posting an image on Facebook showing him with his boot on a corpse, smiling.

[263] On 14 February 2021, Eyad Al-Gharib, a former Syrian intelligence officer, was convicted by the Higher Regional Court of Koblenz, Germany of assisting the torture of prisoners under the process of Universal Jurisdiction.

[265] Al-Gharib was accused of being a part of a police unit that arrested civilians following anti-government protests in the city of Douma and took them to the detention center known as Al-Khatib, Branch 252, where they were subjected to torture.