A Twitter manager has personally apologised to women who have experienced abuse on the social networking site, following rape and bomb threats in the past week, including those against Independent columnist Grace Dent and feminist campaigner Caroline Criado-Perez.
In a series of tweets posted on Saturday, Tony Wang, the general manager of Twitter UK, said:
"I personally apologize to the women who have experienced abuse on Twitter and for what they have gone through.
"The abuse they've received is simply not acceptable. It's not acceptable in the real world, and it's not acceptable on Twitter."
He added that the site was committed to protecting their users from abuse.
Senior director of safety and trust, Del Harvey, and Mr Wang also posted a joint statement on the site's blog, stressing that Twitter has now clarified their rules on abusive behaviour amid an increasing backlash over so-called "trolls".
The move comes as police revealed they are investigating allegations by eight people of abuse on the social networking site.
In a joint statement, Mr Harvey and Mr Wang said:
"It comes down to this: people deserve to feel safe on Twitter.
"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 behaviour was, or could ever be, acceptable."
Twitter was pushed into 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 bomb threat tweet was sent to Dent, Guardian columnist Hadley Freeman and Mayer, which Dent took a screen grab of and posted for her Twitter followers to see.
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.
The company has since added an "in-tweet" report button so people can report abusive behaviour directly from a tweet.
Mr Harvey and Mr Wang 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."
In separate incidents, Labour MP Stella Creasy and campaigner Caroline Criado-Perez, who successfully fought for a woman's face to appear on £10 banknotes, were threatened on Twitter with rape. Two arrests have already been made in relation to those threats.
In a statement, Scotland Yard said an investigation by their e-Crime Unit into eight allegations had been launched into all the claims.
The force said: "Detectives from the Specialist Organised & Economic Crime Command have taken responsibility for the investigations into a number of allegations recently made to the MPS relating to allegations of malicious communication made on the social networking site Twitter.
"The Police Central e-Crime Unit (PCeU), who hold the police national cyber-crime remit, is now investigating allegations made by eight people that they have been subject to harassment, malicious communication or bomb threats.
"Whilst outside PCeU's cyber operational remit, the MPS has taken the decision to centralise the individual investigations, including three that are outside London, to make the most effective use of resources avoid duplication by separate."
The anonymous Twitter accounts from which the bomb threats originated were suspended, although screen grabs were widely circulated online.
Today, Steve White, of the Police Federation, said the problem was "unpoliceable" and more needed to be done by social media organisations.
He told BBC Breakfast: "The organisations that run these social media platforms probably need to take a long, hard look, they need to take some responsibility.
"It's much like when you go into a shop - there are prevention measures within shops, whether it be security guards or things locked away that you can't get to, which is going to prevent crime, and I think social media sites need to think long and hard about being able to prevent it from happening in the first place.
"Crime has completely changed. Internet crime and e-crime, including the kind of trolling that we've seen this week, is hugely on the rise. Members of the public don't really understand what to do about it as well, so it goes unreported.
"We can't possibly deal with every single comment that someone doesn't like on these social media platforms, but I think the Government's got to take a long, hard look at resources and have got to understand that there is a changing face of crime in this country, and the police service needs to adapt to that and the resources need to be there to do it."