Robin Williams' daughter tells of online abuse after dad's death

Robin Williams' daughter has abandoned her online social media accounts in disgust following what she called "cruel and unnecessary" messages after her father's death, a move that has prompted Twitter to explore how it handles such situations.

Zelda Williams, 25, wrote that she was stepping away from her Twitter, Tumblr and Instagram accounts "for a good long time, maybe forever." The move came after at least two users upset the grieving actress by sending disturbing images and verbal attacks.

In one of her last tweets, Williams asked fellow users to report her alleged tormentors to Twitter managers. "I'm shaking," she wrote. One included a Photoshopped image of Robin Williams purporting to be his corpse.

Well-wishers and fans online quickly rallied to Zelda Williams' defense, and the accounts of both alleged bullies were suspended by Wednesday.

"We will not tolerate abuse of this nature on Twitter," Twitter said in a statement Wednesday afternoon. "We have suspended a number of accounts related to this issue for violating our rules and we are in the process of evaluating how we can further improve our policies to better handle tragic situations like this one."

Last summer, Twitter introduced a one-click button to report abuse and updated its rules to clarify that it will not tolerate abusive behavior.

Before being harassed online, Zelda thanked her Twitter followers for donating to St. Jude Children's Research Hospital in memory of her father. "I'm overwhelmed. The charity meant the world to him, as it does to me," she tweeted.

The Broadway community honored Robin Williams Wednesday night by dimming marquee lights for one minute at 7:45 p.m. Williams had been on Broadway several times, most recently as a restless tiger ghost in 2011 in "Bengal Tiger at the Baghdad Zoo."