New Delhi (CNN Business) Two police raids in two days on Australia's national broadcaster and a prominent journalist have raised concerns about press freedom in the country.

Police searched the offices of the Australian Broadcasting Corporation (ABC) in Sydney on Wednesday, saying in a statement they were acting on a "referral" from the country's defense forces over "allegations of publishing classified material."

and vowed to stand by its journalists. ABC linked the police investigation to a series of stories it published in 2017 called "The Afghan Files," which revealed allegations of unlawful killings and misconduct by Australian special forces in Afghanistan . The network slammed the raidsand vowed to stand by its journalists.

"This is a serious development and raises legitimate concerns over freedom of the press and proper public scrutiny of national security and defense matters," ABC Managing Director David Anderson said in a statement emailed to CNN. "The ABC stands by its journalists, will protect its sources and continue to report without fear or favor on national security and intelligence issues when there is a clear public interest," he added.

John Lyons, the network's executive editor and head of investigative journalism, tweeted on Wednesday that the warrant allows police to "add, copy, delete or alter" material on ABC's computers.

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