Social networking site Twitter has issued new rules to help clamp down on abusive behavior, The Daily Telegraph reports.

The company has updated its rules to make it clear that abuse will not be tolerated, and has put extra staff in place to handle reports of abuse, it said.

The move comes as police revealed they are investigating allegations by eight people of abuse on the microblogging site.

Scotland Yard said its e-crime unit is looking into the claims, three of which involve incidents outside London.

Twitter found itself in the spotlight after three female journalists said they had been the subject of bomb threats on the site and two received threats of rape.

The revelations sparked a backlash online, with an online petition calling for Twitter to add a "report abuse" button to tweets attracting more than 120,000 signatures.

In a message posted on its blog today, Twitter's senior director for trust and safety, Del Harvey, and UK general manager Tony Wang said it has updated its rules in light of feedback from customers. "It comes down to this: people deserve to feel safe on Twitter," they said.

The company has updated its rules, clarifying that it will not tolerate abusive behavior, they said, adding that an "in-tweet" report button has been added so people can report abusive behavior directly from a tweet.

"We want people to feel safe on Twitter, and we want the Twitter rules to send a clear message to anyone who thought that such behavior was, or could ever be, acceptable," they wrote.

They said additional staff are being added to the teams which handle abuse reports and the company is working with the UK Safer Internet Centre, which promotes the safe and responsible use of technology.

"We are committed to making Twitter a safe place for our users," they said, adding: "We're here, and we're listening to you."

The bomb threat tweet was sent to Guardian columnist Hadley Freeman, Independent columnist Grace Dent and Europe editor of Time magazine Catherine Mayer, which Dent took a screen grab of and posted for her Twitter followers to see.