At least 400 emails that Hillary Clinton sent or received through her private computer server while secretary of state contained classified material, according to the State Department’s latest update Wednesday from its ongoing review of more than 30,000 emails.

In response to a public records lawsuit, the department released another 6,300 pages of the Democratic presidential candidate’s emails after partially or entirely redacting any containing sensitive U.S. or foreign government information on a range of issues.

None was marked as classified during Clinton’s tenure, department officials say, but intelligence officials say some material was clearly classified at the time. Clinton has insisted she did not send or receive any information marked as classified.