The US State Department released over 4,000 more of the emails former secretary of state Hillary Clinton kept on a private server Monday and revealed that some 150 others have been retroactively classified. Reporters and Clinton's rivals as she campaigns for the 2016 Democratic presidential nomination began scouring 7,000 additional pages of messages from the mails she handed over earlier this year after coming under fire for operating the unofficial server.

But perhaps the greater danger to her, with no smoking gun emerging immediately as the hunt began, lay in the mails which officials said had now seen their security status upgraded to "classified" or above, implying they should not have been sent.

Copyright Agence France-Presse, 2015