Anti-hate advocates are calling on Facebook to ban posts denying the Armenian genocide, which led to the deaths of over 1.5 million ethnic Armenians, saying the social media giant’s policy on hate speech fails to address crimes against humanity, Business Insider reports.

The call to action follows Facebook’s October announcement that it would ban posts denying the Holocaust, which came after pressure from human rights groups, Holocaust survivors, and a 500-plus company ad boycott. However, the change did not include the denial of other genocides, such as the Rwandan and Armenian genocides.

“They have an obligation to responsibly address all genocide,” said Arda Haratunian, board member for the Armenian General Benevolent Union (AGBU), the largest non-profit dedicated to the international Armenian community. “How could you not apply the same rules across crimes against humanity?”

Now, voices from across the Armenian diaspora and anti-hate groups are calling for the company to change its policy. In November, the Armenian Bar Association penned a letter to Facebook and Twitter (which banned posts denying the Holocaust in the days after Facebook did), proposing that they expand their ban to posts denying the Armenian genocide,

“It made us hopeful, because it was a sign that Facebook is taking steps towards fixing its speech problem,” said Lana Akopyan, a lawyer specializing in intellectual property and technology, and member of the Armenian Bar Association’s social media task force. The Armenian Bar Association has yet to receive a response from either company, Akopyan told Business Insider.

Facebook’s current hate speech policy prohibits posts that directly attack a protected group, including someone of a racial minority, certain sexual orientation or gender, or religion. But the platform lacks a cohesive response to other “harmful false beliefs,” like certain conspiracy theories, said Laura Edelson, a PhD candidate at NYU who researches online political communication. Rather than a systematic approach to harmful misinformation, Edelson likened Facebook’s strategy to a game of “whack-a-mole.”

“You are allowed to say, currently, the Armenian genocide is a hoax and never happened,” said Edelson. “But you are not allowed to say you should die because you are an Armenian.”

The Anti-Defamation League (ADL), which successfully lobbied for social media companies to ban Holocaust denial, is also supporting the calls for change.

“ADL believes that tech companies must take a firm stance against content regarding genocide and the denial or diminishment of other atrocities motivated by hate,” said an ADL spokesperson in a statement to Business Insider. “Tech companies should, without doubt, consider denial of the Armenian genocide to be violative hate speech.”

Dr. Gregory Stanton, founding president of human rights nonprofit Genocide Watch, says that denial is a pernicious stage of genocide, since it seeks to erase the past and can predict future violence.

“Denial occurs in every single genocide,” said Stanton. “I think it’s irresponsible…. with Facebook’s incredible reach, it absolutely should be taken down.”