Washington: Top aides to former US Secretary of State Hillary Clinton fretted over how she would be portrayed after the 2012 Benghazi attacks that killed the US ambassador to Libya and three other Americans, emails released on Friday showed.

The emails also showed Clinton received information on her personal email account about the Benghazi attacks that was classified ‘secret’ by the FBI just prior to their release.

Clinton, the frontrunner for the Democratic presidential nomination in 2016, has come under criticism for using a personal email account, hosted on a private server in her New York state home, instead of a government one for messages she sent and received as secretary of state.

The move by the FBI to classify some of the material could further fuel criticism that she handled sensitive information on her private email.

But State Department spokeswoman Marie Harf told that the information classified by the FBI amounted to ‘less than two sentences.’

‘The email and the information in this email ... was not classified at time it was sent,’ Harf said.

The emails released on Friday did not appear to support for Republican accusations that Clinton was involved in efforts to downplay the role of Islamic militants in the attacks on a US diplomatic compound and CIA base in Benghazi. Nor did they indicate that Clinton was personally involved in decisions that resulted in weak security at the Benghazi outposts.

But the correspondence did offer a glimpse into how Clinton's team was concerned about her image immediately afterward.

A senior adviser to Clinton, Jake Sullivan, forwarded an email from a State Department official about positive media coverage of a statement she gave on 12 September 2012, the day after the killings.

‘Really nice work guys,’ State Department official Matthew Walsh wrote in an email to other staffers, which linked to a story on the Slate news site praising Clinton's comments about Benghazi as ‘her most eloquent news conference as secretary of state.’

Sullivan, Clinton's deputy chief of staff, passed the email on to her with the letters ‘FYI.’

In another email from September 2012, Sullivan assured the secretary of state that she had used the correct language to describe the lead-up to the Benghazi attacks.

US officials' exact wording of the attackers' motivation had become important because the Obama administration initially said the assaults were a spontaneous protest against an anti-Islamic film posted on the Internet.

The US ambassador to the United Nations at the time, Susan Rice, drew heavy criticism from Republicans for making this claim on several Sunday TV shows, even though intelligence indicated within hours after the attacks that they had been the carefully planned work of Islamist militia members.

Sullivan assured Clinton that her language when discussing the attacks in public had been correct.

‘You never said spontaneous or characterized the motives, in fact you were careful in your first statement to say we were assessing motive and method,’ he wrote in an email.

A number of the emails to Clinton, some from high-ranking officials, are flattering to the former first lady.

After Clinton appeared on television the day after the Benghazi attack, Liz Sherwood-Randall, a White House official, sent a message to her via Sullivan which described Clinton's performance as ‘emphatic and unflinching and inspiring; she was wise and steady and strong. My 80 year old mother called from LA to say, 'She was like our rock of Gibraltar.'‘

Long a focus of Republican investigators in Congress, accusations that Clinton was negligent on Benghazi are putting her under more intense scrutiny now that she is running for the Democratic Party nomination in the 2016 presidential election.

Republicans say the Obama administration was lax about the security of US personnel in Libya and then misled the public about the nature of the attacks, but various congressional probes have produced little damaging evidence.

State Department spokeswoman Marie Harf said that the 296 emails released on Friday ‘do not change the essential facts or our understanding of the events before, during or after the attacks.’

They were the first instalment of a rolling release of 55,000 pages of emails from her time as secretary of state between 2009 and 2013 that are due to be released in the coming months.

Clinton or her aides have deleted another 30,000 emails which she has termed as personal from the same private account, causing Republicans in Congress to accuse her of picking and choosing what she wants to make public.

Rep. Trey Gowdy, the Republican who heads the Benghazi probe in the House of Representatives, said the emails made public on Friday ‘continue to reinforce the fact that unresolved questions and issues remain as it relates to Benghazi.’

He also complained that there was a significant gap in the emails between late April and 4 July 2012, a period when threats from militants in Benghazi were being more regularly reported.