Twitter on Tuesday unveiled a new initiative to crack down on "abusive accounts," in the latest attempt by the social network to curb online harassment.

The effort comes with Twitter and other social platforms struggling to keep up with online abuse, especially from anonymous accounts.

"We're taking steps to identify people who have been permanently suspended and stop them from creating new accounts," said a statement from Twitter engineering vice president Ed Ho.

"This focuses more effectively on some of the most prevalent and damaging forms of behavior, particularly accounts that are created only to abuse and harass others."

Twitter seeks to foster a healthy exchange on public issues, but the messaging platform has also been used as a tool to harass or "troll" people, with perpetrators often creating new accounts after being suspended.

Former chief executive Dick Costolo acknowledged in 2015 that Twitter had lagged in dealing with online abuse, and that the situation had hurt its efforts to grow.

"Making Twitter a safer place is our primary focus," Ho said in the statement.

"We stand for freedom of expression and people being able to see all sides of any topic. That's put in jeopardy when abuse and harassment stifle and silence those voices. We won't tolerate it and we're launching new efforts to stop it."

Another effort unveiled Tuesday will allow users to enable "safe search" which removes Tweets that "contain potentially sensitive content" and tweets from blocked and muted accounts, Ho said.

He added that Twitter's engineers are working on identifying "potentially abusive and low-quality replies so the most relevant conversations are brought forward."

He said these tweets will still be accessible to those who seek them out.

The changes are expected to roll out "in the coming weeks," he added.

Twitter has faced problems of harassment since its inception, and cracking down has been difficult because users can create an account anonymously with only an email account.