PORTLAND, Ore. (KOIN) — A federal memo obtained by KOIN 6 News says power companies in Oregon and Washington have reported people physically attacking substations, with two of the recent attacks taking place at Clackamas substations.

This comes after authorities in North Carolina say someone intentionally shot and damaged substations in that state, leaving tens of thousands of families without power.

That federal memo says that are criminals using hand tools, arson and firearms to attack substations. Federal authorities are saying it’s a response to an online call for attacks on critical infrastructure, with the aim of violent anti-government activity.

Doug Johnson with Bonneville Power Administration says the company is beefing up security after one of its substations in Clackamas was attacked over the Thanksgiving holiday, and Portland General Electric also confirmed one of their Clackamas substations was also attacked around the same time.

“This compromises public safety in a lot of ways and it’s a very serious offense,” Johnson said. “We know that it was suspicious activity. This was not an accident. Somebody meant to do harm to that facility.”

Local sociologist Randall Blazak, who studies extremist groups for a living, explained why this kind of violence is happening on a larger scale.

“We are seeing that all over again in kind of tenfold now because that anti-government movement is no longer sort of extremist in bunkers and rural Montana. There are people in suburbs and people in office towers, and the anti-government movement has grown largely because of the internet and social media and the spread of conspiracy theories,” he said. “The infrastructure has been a target of anti-government extremists for quite some time. I mean, we saw a ramping up of this threat after the Oklahoma City bombing in 1995.”