Officials announced on Sunday that a county in North Carolina has declared a state of emergency after two power substations were shot at and left riddled with bullet holes, leaving thousands of homes in the dark.

No one knows who launched the attack on the equipment on Saturday, which left over 40,000 people in the dark, but authorities say the incident in Moore County is being investigated as a deliberate and criminal act.

During a press conference, Moore County Sheriff Ronnie Fields stated, "No group has acknowledged or accepted responsibility," adding that the FBI was collaborating with state investigators to identify those responsibly.

Fields stated that someone "opened fire on the substation, as well as the other one," but no motive for the crime has yet been determined.

Saturday around 7 p.m., the lights began to go out.

He described the attack as "targeted" and stated that law enforcement would provide overnight protection for the substations and businesses.

Fields stated, "Last night in Moore County, we encountered something for the first time." However, I assure you that we will get through this.

Sunday night, power outage.us reported that approximately 37,000 county residents remained without power.

The power outage has necessitated a curfew from Sunday at 9 p.m. until Monday at 5 a.m.

As long as the emergency order is in effect, this curfew could continue through the week.

Monday, all county schools were also closed.

"An attack like this on critical infrastructure is a serious, intentional crime, and I expect state and federal authorities to investigate thoroughly and bring the perpetrators to justice," tweeted North Carolina Governor Roy Cooper.

Duke Energy spokesperson Jeff Brooks stated that customers could be without power for days, prompting a local sports complex to serve as a shelter on Sunday night.

Several damaged pieces of equipment will need to be replaced, he said.

Brooks stated at a press conference, "We are looking at a fairly complex repair involving fairly large equipment, so we do want residents to be aware that this will be a multi-day restoration for the majority of customers, potentially lasting until Thursday."