[20] Over 100 massacres of Tamil civilians were committed by the Sri Lankan security forces throughout the civil war, resulting in the deaths and injuries of tens of thousands.

[25] Within months of the Sri Lanka military returning to the eastern province in June 1990 following the resumption of war, thousands of Tamils disappeared in the custody of the security forces.

[26] In 2008, Human Rights Watch accused the Sri Lankan government of being responsible for "widespread abductions and disappearances" of hundreds of Tamils since the war resumed in 2006, with most feared dead.

[30] A report by the Human Rights Data Analysis Group and the International Truth and Justice Project found that at the end of the war between 17 and 19 May 2009, an estimated 503 Tamils, including at least 29 children, were subjected to enforced disappearance after surrendering to the Sri Lankan Army around Vadduvakal Bridge in Mullaitivu.

"[31][32] After visiting Sri Lanka in 2013, Navi Pillay, then UN High Commissioner for Human Rights, highlighted the plight of Tamil families with missing persons by stating she had "never experienced so many people weeping and crying," and "never seen this level of uncontrollable grief".

[36] Lutz Oette, an international law specialist, examined the reported cases of enforced disappearances of thousands of Tamils between 1984 and 1997 and stated that they fell within the definition of genocidal acts.

It then proceeded to shell using heavy weapons three consecutive NFZs killing large numbers of civilians despite having foreknowledge of the impact through information provided by its UAVs, as well as by the UN and the ICRC.

[40] In 2014 an international team of investigators for the International Crimes Evidence Project (ICEP) and in 2015 the Report of the OHCHR Investigation on Sri Lanka (OISL) both found that large numbers of civilians, mostly women and children, queuing at food distribution centers were deliberately killed by government shelling despite there being no LTTE activity and the government having knowledge of the time and location of the distributions.

[43] During the final days of the war, the Sri Lankan Army also engaged in indiscriminate executions of Tamils, civilians as well as fighters who surrendered waving a white flag.

[45][47] Commenting on the systematic destruction of mass burial sites by the government, William Schabas, a professor of international law, stated that "when people destroy evidence it's because they know they've done something wrong".

[50] Drawing on the parallels between the Srebrenica and the Vanni cases, human rights lawyer Anji Manivannan argued that the Sri Lankan government leaders and military commanders possessed specific intent of genocide in targeting a substantial part of the Tamil population of the Vanni in 2009 for destruction, namely, its numeric size, significance and the presence of the group's leadership; and committed three acts of genocide, namely, killing by intentional shelling of the UN hub, hospitals and food distribution lines; "causing serious bodily or mental harm" by maiming around 30,000 civilians and using sexual violence against hundreds of women and girls; and "deliberately inflicting conditions of life to bring about the group's physical destruction" by denying humanitarian aid.

[52] Tamil human rights group PEARL published a report in September 2024 arguing that there was a sufficient legal basis to describe the massacre as a genocide.

Following the precedent set by ICTR, ICTY and UN Fact-Finding Mission on Myanmar, it argued that genocidal intent can be inferred from circumstantial evidence, such as disproportionate and systematic use of force against Tamils in the Vanni and statements of Defence Secretary conflating civilians with combatants.

[54] Former UN staffer Benjamin Dix, who had worked in the Vanni between 2004 and 2008, stated it was a "very fair" assessment that the Sri Lankan Army committed genocide, describing the final offensive as "destruction of the Tamil community".

[56][57][58] On 18 May 2010, Channel 4 News broadcast interviews with two Sri Lankan soldiers who claimed that they had been given orders from "the top" to summarily execute all ethnic Tamils, civilians as well as fighters.

"[46]Another retired soldier who served on the front lines told The New York Times that they should "beg for forgiveness" for what they had done during the final offensive, recounting that they were "encouraged to be merciless" and they "went mad".

[65] Commenting on Nambiar's statement that UN's role should be "compatible with the government," Francis Boyle, professor of international law, denounced the UN and its top officials as aiding and abetting Tamil genocide.

[72][73][74] There has been widespread and systematic sexual violence against the Tamil population by the Sinhalese-dominated Sri Lankan security forces with the approval of the highest levels of the government both during and after the war.

[91] Piers Pigou, a human rights investigator with 40 years experience of interviewing torture survivors, described the levels of sexual abuse perpetrated against Tamils by the Sri Lankan authorities as "the most egregious and perverted" that he had ever seen.

"[96] The burning of the Jaffna Public library in 1981 by an organised Sinhalese mob has been described by Damien Short as a 'classic genocidal tactic', where the cultural roots of the Tamils was being attacked, with old and irreplaceable documents being destroyed.

[103] This resulted in a significant demographic shift, with the resettled farmers contributing to an increase in the Sinhalese population in the northeast dry zone, thus promoting Sinhala-Buddhist hegemony in the area.

[109][110] The University Teachers for Human Rights has described this as ethnic cleansing of Tamils occurring with the support of the government since the 1956 Gal Oya riots.

[109] In 1985, a Sri Lankan government appointed study group recommended using Sinhala colonisation to break the link between the Tamil majority regions of the north and east.

[112] Following the end of war in 2009, Sinhalese officials and settlers in Weli Oya have expressed their desire to take more land further north in order to "make the Sinhala man the most present in all parts of the country".

[7] The Tribunal found that the evidence conclusively demonstrated, beyond any reasonable doubt, that the Government of Sri Lanka committed the following genocidal acts:[7] (a) Killing members of the group, which includes massacres, indiscriminate shelling, the strategy of herding civilians into so-called "No Fire Zones" for the purpose of mass killings, and targeted assassinations of prominent Tamil civil leaders who could expose the Sri Lankan genocide to the world.

[114][115] To mark the first Tamil Genocide Remembrance Day on 18 May 2023, Canadian Prime Minister Justin Trudeau issued the following statement: "The stories of Tamil-Canadians affected by the conflict – including many I have met over the years in communities across the country – serve as an enduring reminder that human rights, peace, and democracy cannot be taken for granted.

"[118] On 21 June 2023, The Island reported that the Canadian High Commission in Sri Lanka confirmed that Prime Minister Trudeau's statement marking the first Tamil Genocide Remembrance Day reflected Canada's stance.

[122][123] On 25 January 2019, a resolution passed by the Municipal Council of the City of Barcelona called for an international investigation into "the genocide perpetrated by the government of Sri Lanka".

[125] The late Indian Prime Minister Indira Gandhi declared the Black July pogrom to be a genocide against the Tamil people on 14 August 1983.

[132] In January 2021 Canadian Mayor Patrick Brown promised to build a monument commemorating the victims of Tamil genocide after the Mullivaikkal memorial in Sri Lanka was torn down by the authorities.