Under its new, more detailed harassment policy, Facebook will bar content that degrades or sexualises public figures, including celebrities, elected officials and others in the public eye.

Existing policies already prohibit similar content about private individuals.

Another change will add more protections from harassment to government dissidents, journalists and human rights activists around the world.

Lastly, the company announced it will ban all co-ordinated harassment, in which a group of individuals work together to bully another user. That change will apply to all users.

"We do not allow bullying and harassment on our platform, but when it does happen, we act," Antigone Davis, Facebook's head of global safety, wrote in a blog post.

The changes come amid mounting criticism of the company's handling of hate speech, misinformation and negative content.

Concerns about harassment range from teenagers bullying each other on Instagram to the co-ordinated abuse of journalists and dissidents by groups linked to authoritarian governments.

Last week, former Facebook data scientist Frances Haugen told Congress the company has done too little to address its responsibility for spreading harmful content, and too often chooses profit over its users' best interests.

Days later, the company announced it would introduce new features designed to protect kids, including one encouraging them to take a break from the platform.

Australian Associated Press