Prosecutors in Washington, D.C. should immediately drop felony riot charges against reporters who were detained on Friday covering violent protests against Donald Trump’s presidential inauguration, the International Press Institute (IPI) said today.

Six reporters face up to 10 years in prison and fines of up to $25,000 if convicted. They maintain that they were merely covering protests in which demonstrators vandalised property around the U.S. capital when police swept them up with protestors.

Those detained include Evan Engel of Vocativ, web documentary producer Jack Keller, independent journalists Matt Hopard and Shay Horse, and freelancer Aaron Cantú. Alex Rubinstein, a reporter for Russian-government-backed broadcaster RT America, was also detained.

The six were arraigned on Saturday and released pending further hearings in February and March.

Arrest reports in the cases were virtually identical and included no specific accusations about what the journalists were alleged to have done. The reports stated that the reporters were present at the scene where a “crowd” engaged in crimes – including breaking windows, lighting fires and damaging vehicles – but made no distinction between those participating in the violence and those covering it.

IPI Director of Advocacy and Communications Steven M. Ellis criticised the arrests, as well as the decision to press charges.

“We are alarmed about the chilling effect this will have on coverage of future protests and the degree to which it undermines journalists’ ability to act as public watchdogs,” he said in a letter to U.S. Attorney for the District of Columbia Channing D. Phillips.

“The events of Jan. 20, including the police response, were of significant public interest. Prosecuting journalists who were present to cover these events not only hinders the public’s ability to receive information about these and future events in stark disrespect of the First Amendment, it ultimately will undermine attempts to ensure accountability for inappropriate behaviour, further eroding trust in law enforcement and weakening democratic society.”

Ellis urged Phillips “not to allow that to happen” and called for the charges to be dropped absent evidence directly linking one of the reporters to the commission of a crime.

The charges come amid an increasingly troubling backdrop for press freedom in the United States less than a week into Trump’s presidency. Since taking office, Trump has continued to push the falsehood that his inauguration crowd was larger than that at President Barack Obama’s 2009 inauguration and he has accused media outlets of lying in reports debunking the claim.

On Saturday, Trump delivered an address at the Langley headquarters of the U.S. Central Intelligence Agency, which he previously accused of Nazi-like behaviour, and falsely blamed the media for inventing his feud with U.S. intelligence agencies. He told attendees: “I have a running war with the media. They are among the most dishonest human beings on earth, right?”

That same day, White House Press Secretary Sean Spicer used his first briefing to repeat Trump’s accusation that media outlets lied about the size of his inauguration crowd and refused to take any questions. On Sunday, Trump adviser Kellyanne Conway defended Spicer’s assertion of multiple, easily-debunked falsehoods, saying that he had relied on “alternative facts”.

Early this week, in a move reminiscent of then-Canadian Prime Minister Stephen Harper’s ban on unauthorised contacts between government scientists and journalists, the Trump administration imposed communications freezes on multiple government agencies, including the Environmental Protection Agency (EPA), the Department of Agriculture (USDA) and others.

The move, reportedly temporary, banned staffers from issuing press releases or posting on official social media accounts. Employees in the EPA’s public affairs office were directed to forward all inquiries from journalists to the Office of Administration and Resources Management and the agency was ordered to remove a page on climate change from its website.

Some of the directives were later rescinded following public outcry, including the gag order on the USDA and the order to remove the EPA’s climate change page.

On Wednesday, Spicer denied White House involvement in the gag orders. However, his comments were at odds with those of Doug Ericksen, part of Trump’s transition team at the EPA, who said that any studies or data from the agency must now be reviewed by political appointees before it can be made public. Ericksen said that review also includes any content posted on the EPA’s website.