Canadian government and law enforcement staff are scrambling to figure out how the digital hacking collective Anonymous gained access to classified Canadian government information.

On Monday, the group released to the media the first of what it says will be many sensitive documents.

It posted what appeared to be a 2014 Treasury Board memo about funding of the Canadian Security Intelligence Service’s overseas communications capabilities.

The security breach is an escalation in attacks by Anonymous against the federal government. Until now, the group had mostly taken down government websites, a tactic experts say is like a digital sit-in protest.

Anonymous said in a video it will continue to release documents until the RCMP officers who shot and killed a protester with the group in British Columbia are arrested.