A federal grand jury on Thursday indicted Jack Teixeira, the Massachusetts Air National Guard member accused of posting secret and sensitive military documents on social media, on six counts related to his retention and transmission of those documents.

“The unauthorized removal, retention and transmission of classified information jeopardizes our nation’s security,” acting U.S. Attorney Joshua S. Levy said in a statement Thursday. “Individuals granted access to classified materials have a fundamental duty to safeguard the information for the safety of the United States, our active service members, its citizens and its allies. We are committed to ensuring that those entrusted with sensitive national security information adhere to the law.”

The documents Teixeira is accused of taking and posting to Discord, a social media site popular with people playing online games, included one classified as “secret” and five with “top secret” or Sensitive Compartmented Information designations. At least three of the documents involve Ukraine.