Acting U.S. Attorney Michael Sherwin has said that materials stolen during yesterday’s coup attempt on the U.S. Capitol by rioters supporting President Donald Trump’s attempts to overturn the election may constitute a breach of national security.

“Materials were stolen, and we have to identify what was done, mitigate that, and it could have potential national security equities,” Sherwin said. “We just don’t know the extent of that damage at this point—if there was damage, we don’t know the extent of that.”

Specifically, Sherwin said that rioters stole electronics from U.S. senators’ offices that could’ve contained sensitive information relating to domestic and foreign intelligence and other sensitive matters, Reuters reports.