WikiLeaks founder Julian Assange has been indicted in the United States for violating the Espionage Act by obtaining and publishing secret military documents in 2010, The New York Times has reported.

“Assange’s actions risked serious harm to United States national security to the benefit of our adversaries,” the US Justice Department said in a statement on Thursday, according to The Guardian. In 2010, WikiLeaks had released a tranche of military and diplomatic documents, including those pertaining to the US wars in Iraq and Afghanistan, uncovering potential war crimes.

In April, US prosecutors revealed that Assange was charged with one count of conspiracy for conspiring to hack a Pentagon computer system in 2010, CNN reported. Earlier this month, Assange refused to be extradited to the US.

Justice Department officials did not explain why Assange was charged under the Espionage Act, a move that has raised questions about the freedom of press under the First Amendment to the US Constitution. The officials said most of the new charges related to obtaining secret documents and not publishing them.

“Some say that Assange is a journalist and that he should be immune from prosecution for these actions,” said John Demers, head of the Justice Department’s National Security Division. “The department takes seriously the role of journalists in our democracy and we thank you for it. It is not and has never been the department’s policy to target them for reporting.”

WikiLeaks editor-in-chief Kristinn Hrafnsson called the indictment “evil of lawlessness in its purest form”. “With the indictment, the ‘leader of the free world’ dismisses the First Amendment – hailed as a model of press freedom around the world – and launches a blatant extraterritorial assault outside its border, attacking basic principles of democracy in Europe and the rest of the world.”

Assange is currently in jail in the United Kingdom after being sentenced to 50 weeks in prison on May 1 for skipping bail in 2012 and seeking refuge in the Ecuadorian embassy in London. He was kicked out of the embassy last month.