Facebook said on Wednesday that it would ban white nationalist content from its platforms, a significant policy change that bows to longstanding demands from civil rights groups who said the tech giant was failing to confront the powerful reach of white extremism on social media.

The threat posed by white nationalism on Facebook was violently underlined this month when a racist gunman killed 50 people at two mosques in New Zealand, using the platform to post live video of the attack. Facebook removed the video and the gunman’s account on Facebook and Instagram, but the footage was widely shared on YouTube, Twitter and Reddit.

The company had previously banned white supremacist content from its platforms but maintained a murky distinction between white supremacy, white nationalism and white separatism. On Wednesday, it said that its views had been changed by civil society groups and experts in race relations and that it now believed “white nationalism and separatism cannot be meaningfully separated from white supremacy and organized hate groups.”

Kristen Clarke, the president of the Lawyers’ Committee for Civil Rights Under Law, which helped Facebook shape its new attitude toward white nationalism, said the earlier policy “left a gaping hole in terms of what it provided for white supremacists to fully pursue their platform.”