A controversial website which has been linked to the suicides of two teenagers after enduring months of online bullying has introduced a range of changes to make sure it is safe.

Ask.fm co-founders Ilja and Mark Terebin said an audit a more prominent "report button" will be included in the site and more staff hired to work as moderators.

The changes comes following the deaths of 14-year-old Hannah Smith, who hanged herself after being bullied by users of the website and the suicide of Daniel Perry, 17, of Dunfermline, who has also been linked to the site.

Daniel was bribed over online phone service Skype but was reportedly urged to commit suicide by anonymous users of Ask.fm three months before he died.

Ask.fm will also create an extra website for parents, as well as incentives to encourage people to register to use the site.

Specsavers, Vodafone, Laura Ashley, EDF Energy and charity Save the Children all pulled adverts from the website, which pledged to work with police following Hannah's death and instructed law firm Mishcon de Reya to carry out the audit of its site and safety features.

The site's founders said in a statement: "At Ask.fm we want our users to be able to have fun, share information, make friends and express themselves freely. We also want them - particularly our younger users - to be able to do this in a safe environment.

"In the light of recent events highlighting the impact online bullying and harassment we engaged professional advisers to conduct a full and independent audit of our site and its safety features.

"This audit has now been completed. Based on the findings and the recommendations that were made, we can announce our commitment to making changes to Ask.fm's existing policies in three core areas: reporting and moderation, registration, and corporate visibility."