The move comes at a time when social media networks have come into focus for not doing enough to rein in extremist elements, which politicians and others say are using to recruit members and promote their violent agendas.

"The updated language emphasizes that Twitter will not tolerate behavior intended to harass, intimidate, or use fear to silence another user's voice," the online service said in a blog post, entitled "Fighting abuse to protect freedom of expression."

"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."

Ban on 'hateful conduct'

According to the new rules, Twitter would temporarily lock or even permanently suspend users who engage in "hateful conduct." The online service said it would not allow accounts aimed at inciting harm towards others. The network already has a ban on users looking to promote terrorism or making threats of violence.

The new policy also says that creation of multiple accounts with overlapping uses to avoid suspension of a particular account was not allowed.

"The new rules are definitely an improvement," Rabbi Abraham Cooper of the Digital Terrorism and Hate Project at the Simon Wiesenthal Center in Los Angeles told the AP news agency. "But the question is: Will they be accompanied by a more proactive attitude toward making sure repeat offenders are identified and permanently removed?"

Twitter has taken several measures over the past year to curb abuse in order to protect its users' freedom to express. The users already have the option of blocking, muting and reporting abusive behavior.

The US microblogging platform has raised its investments to handle more reports of abuse. It said in February that it reviewed five times as many user reports as it did previously and that it had tripled the size of the support team focused on handling abuse reports.

On Tuesday, German Green lawmaker Volker Beck filed charges against the anti-immigrant, anti-Muslim Pegida movement and some of its followers after he received hundreds of threatening comments including death threats on his Facebook account.

In mid-December, German Justice Minister Heiko Maas said Facebook and other social media networks had agreed to delete comments that violate Facebook's community standards within 24 hours of publication.

ap/msh (AP)