San Francisco: On an average, women receive an abusive or problematic tweet every 30 seconds, reveals an Amnesty International study on Tuesday that buttresses Twitter's reputation as a "toxic" platform for women, especially for politicians and journalists.

Women of colour, (Black, Asian, Latinx and mixed-race women) were 34 per cent more likely to be mentioned in abusive or problematic tweets than White women, showed the findings.

Amnesty International said that one in 10 tweets mentioning Black women politicians and journalists in a sample analysed by the organisation was abusive or problematic.

"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," Milena Marin, Senior Advisor for Tactical Research at Amnesty International said in a statement.

"Twitter's failure to crack down on this problem means it is contributing to the silencing of already marginalised voices," Marin said.

For the study, Amnesty International collaborated with Element AI, a global artificial intelligence software product company.

More than 6,500 volunteers from 150 countries signed up to take part in the crowdsourcing project designed to process large-scale data about online abuse.

Volunteers sorted through 288,000 tweets sent to 778 women politicians and journalists in the UK and the US in 2017.

Politicians included in the sample came from across the US and UK political spectrums.

The journalists included were from a diverse range of US and UK publications including The Daily Mail, The New York Times, Guardian, The Sun, GalDem, Pink News and Breitbart.

"Online abuse against 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," Amnesty International said.

Abusive content violates Twitter's own rules and includes tweets that promote violence against or threaten people based on their race, ethnicity, national origin, sexual orientation, gender, gender identity, religious affiliation, age, disability, or serious disease.

Problematic content was defined as content that is hurtful or hostile, especially if repeated to an individual on multiple or cumulative occasions, but not as intense as an abusive tweet.

When Amnesty International shared its findings with Twitter, the micro-blogging site reportedly requested clarification on the definition of "problematic" "in accordance with the need to protect free expression and ensure policies are clearly and narrowly drafted."