In a fresh bid to combat abusive behaviour, micro-blogging site Twitter is revising its rules to tackle hateful conduct including spreading of terror messages online.

"We believe that protection from abuse and harassment is a vital part of empowering people to freely express themselves on Twitter," Megan Cristina, director, trust and safety at Twitter, posted in a blog.

"The updated language emphasises that Twitter will not tolerate behaviour intended to harass, intimidate, or use fear to silence another user's voice. As always, we embrace and encourage diverse opinions and beliefs but we will continue to take action on accounts that cross the line into abuse," she posted.

Over the past year, Twitter has taken several steps to fight abuse in order to protect freedom of expression.

It has empowered users with tools for blocking, muting and reporting abusive behaviour.

"We evolved our policy to capture more types of abusive behaviour. We've also increased our investment in policy enforcement so that we can handle more reports with greater efficiency, and bolstered educational resources through a new Twitter Safety Centre," Cristina wrote.

One of the areas Twitter found to be effective in this multi-layered strategy of fighting abuse is creating mandatory actions for suspected abusive behaviour such as email and phone verification and user deletion of Tweets for violations.

"These measures curb abusive behaviour by helping the community understand what is acceptable on our platform," the post read.

The change comes when terrorist groups like Islamic State (IS) are using social media platforms like Twitter to spread its agenda and communicate with its followers.