Facebook’s fake news problems extend far beyond Russian trolls interfering in US elections. Overseas, false stories have turned into tools of political warfare — most notably in Myanmar, where government forces have carried out a campaign of ethnic cleansing against the Rohingya, the country’s Muslim minority group.

In an interview with Vox’s Ezra Klein, Facebook CEO Mark Zuckerberg addressed Facebook’s role in fueling and inciting anti-Muslim and anti-Rohingya sentiment. “The Myanmar issues have, I think, gotten a lot of focus inside the company,” Zuckerberg said. “And they’re real issues and we take this really seriously.”

He recalled one incident where Facebook detected that people were trying to spread “sensational messages” through Facebook Messenger to incite violence on both sides of the conflict. He acknowledged that in such instances, it’s clear that people are using Facebook “to incite real-world harm.” But in this case, at least, the messages were detected and stopped from going through.

“This is certainly something that we’re paying a lot of attention to,” Zuckerberg continued. “It’s a real issue, and we want to make sure that all of the tools that we’re bringing to bear on eliminating hate speech, inciting violence, and basically protecting the integrity of civil discussions that we’re doing in places like Myanmar, as well as places like the US that do get a disproportionate amount of the attention.”

Why Facebook came under fire in Myanmar

Close to 700,000 Rohingya refugees have fled to neighboring Bangladesh since last August in the wake of a government crackdown against the minority group. Then-Secretary of State Rex Tillerson officially labeled the crisis an “ethnic cleansing” in November, but the international community has been slow to act on the escalating humanitarian disaster.

The violence in Myanmar highlights the duality of social media in general, and Facebook in particular, as a force for both good and ill.

Activists and reporters use phones and social media to document atrocities, helping evade government censors. But anti-Muslim and anti-Rohingya memes and propaganda spread virulently through Facebook too, inciting violence and eroding support for the Rohingya’s plight. Public-facing accounts of verified government and military leaders — as well as the extremely influential accounts of nationalistic Buddhist monks — included false and inflammatory posts about the Rohingya, the New York Times reported in October.

In a recent report on the Rohingya crisis, Marzuki Darusman, head of the United Nations Fact-Finding Mission on Myanmar, said Facebook “substantively contributed to the level of acrimony and dissension and conflict” in Myanmar. “Hate speech is certainly of course a part of that,” Darusman said. “As far as the Myanmar situation is concerned, social media is Facebook, and Facebook is social media.”

Facebook responded to the criticism by saying in a statement that there “is no place for hate speech or content that promotes violence,” and that it’s been working with experts in Myanmar to address the issue.

Facebook has taken down some posts, including temporarily shutting down the account of an ultranationalist Buddhist monk who posted incendiary content. But the company has also been accused of removing posts that document violence against the Rohingya, which underscores how challenging and complicated it is to even attempt to police the social network.

Zuckerberg told Klein in his interview that Facebook is constantly trying to navigate between these distinctions — deciding what qualifies as hate speech and what’s valid political speech, among other knotty problems. “I think more than a lot of other companies, we’re in a position where sometimes we have to adjudicate those kind of disputes between different members of our community,” he said.

Klein pointed out that while Facebook is a vital tool for information in Myanmar, that it might not get the attention of other markets given its size. Indeed, Facebook’s popularity as a news source in the region has exacerbated Myanmar’s fake news problem. According to CBS News, the number of Facebook users in Myanmar increased from 2 million in 2014 to more than 30 million currently — partly a result of the military junta easing censorship, and partly because of the increasing affordability of smartphones.

“Facebook has become sort of the de facto internet for Myanmar,” Jes Kaliebe Petersen, chief executive of Phandeeyar — a technology company that helped Facebook create its Myanmarese-language community standards page — told the Times. “When people buy their first smartphone, it just comes preinstalled.”

Zuckerberg conceded that Facebook needs to improve as its global reach expands. “Just based on the fact that our headquarters is here in California,” he told Klein, “and the vast majority of our community is not even in the US, I think does make this just a constant challenge for us to make sure that we’re putting due attention on all of the people in different parts of the community around the world.”

Listen to Zuckerberg’s full interview with Klein here: