London-based Amnesty International found that black women politicians and journalists were 84 percent more likely than white counterparts to receive abusive messages on Twitter in 2017.
Female politicians and journalists of colour in Britain and the US are disproportionately targeted for online abuse, according to a crowdsourced study that found they received "problematic messages" every 30 seconds on average.
The assessment – by Amnesty International and artificial intelligence company Element AI – found that black women in these roles were 84 percent more likely than white counterparts to receive abusive messages on Twitter in 2017.
The firms signed up more than 6,500 volunteers from 150 countries to take part in its "Troll Patrol" project to flag and process large-scale data about online abuse.
"Troll Patrol means we have the data to back up what women have long been telling us – that Twitter is a place where racism, misogyny and homophobia are allowed to flourish basically unchecked," said Milena Marin of Amnesty International.
"We found that, although abuse is targeted at women across the political spectrum, women of colour were much more likely to be impacted, and black women are disproportionately targeted."
The volunteers analysed 288,000 tweets mentioning 778 politicians from across the British and American political spectrums, as well as journalists from the likes of The New York Times, The Guardian, The Daily Mail and Breitbart.
It revealed one in 10 messages mentioning black women were "problematic", while women of colour – black, Asian, Latina and mixed-race – were 34 percent more likely to get abusive messages than white women.
London-based Amnesty International said the online abuse towards women cuts across the political spectrum.
"Politicians and journalists faced similar levels of online abuse and we observed both liberals and conservatives alike, as well as left and right-leaning media organisations, were affected," it reported.
The NGO added it had repeatedly asked Twitter to publish data regarding the scale and nature of abuse on their platform, but the company had so far failed to do so.
"This hides the extent of the problem and makes it difficult to design effective solutions," it said.
Vijaya Gadde from Twitter said: "Twitter has publicly committed to improving the collective health, openness, and civility of public conversation on our service."
"Our abusive behaviour policy strictly prohibits behaviour that harasses, intimidates or silences another user's voice," she said, adding that Twitter was investing in technology and tools to identify abusive material.