(NewsNation) — Days after what officials called a targeted attack on power substations in North Carolina, NewsNation has exclusively obtained a recent federal law enforcement memo that warned of something strikingly similar.

The memo reads in part:

Power companies in Oregon and Washington have reported physical attacks on substations using hand tools, arson, firearms and metal chains possibly in response to an online call for attacks on critical infrastructure. … In recent attacks, criminal actors bypassed security by cutting the fence links, lighting nearby fires, shooting equipment from a distance or throwing objects over the fence and onto equipment.

Federal Law Enforcement officials

Officials told NewsNation Tuesday it is too early to know a motive for the gunfire damage that caused widespread power outages in Moore County, North Carolina, but there have been similar cases of vandalism and plots in North Carolina and across the country in recent months.

On Nov. 11, for example, sheriff’s deputies in Jones County, North Carolina, reported that criminal vandalism had caused 12,000 people to lose power for days.

That investigation remains ongoing and authorities say no suspects have been identified or arrested.

In another instance back in February, the Department of Justice secured guilty pleas from three men accused of plotting to shoot substations across the country with powerful rifles.

Federal officials said the defendants were white supremacists and planned to cause millions in damage and social unrest.

Federal authorities have warned of domestic terrorism-related threats to critical infrastructure for years. The Department of Homeland Security renewed that concern in a terrorism alert bulletin issued publicly on Nov. 30.

It reads, in part:

Targets of potential violence include: public gatherings, faith-based institutions, the LGBTQI+ community, schools, racial and religious minorities, government facilities and personnel, U.S. critical infrastructure, the media, and perceived ideological opponents.

The Department of Homeland Security

Officials called the North Carolina outages over the weekend a set of coordinated attacks on power substations.

“It appears to be an intentional, willful and malicious act and the perpetrator will be brought to justice and prosecuted to the fullest extent of the law,” said Sen. Tom Mcinnis, R-N.C.

The outages — at their peak affecting around 45,000 homes — caused residents to lose heat, schools to close and some to turn to charities to cook them food.

“And I said I’m gonna stop out there and get me something to eat. Because eating out of the can all the time just don’t get it,” one North Carolina resident said.

According to The News and Observer of Raleigh, Duke Energy was the company that had its electrical substations damaged, affecting tens of thousands of Moore County residents.

As of Tuesday, about 73% of the more than 47,000 Duke Energy customers served in the county were reportedly still without power.

The company said Tuesday evening it “anticipates having nearly all customers restored by 11:59 p.m. Wednesday.”

Additionally, Moore County Schools announced Tuesday afternoon that schools will be closed Wednesday and Thursday due to the outages.