According to local authorities, four power stations in Northwest Washington were "vandalized" by thieves on Sunday, leaving thousands of homes without electricity, according to a report by The Daily Caller.

Over 14,000 Tacoma households lost power as a result of vandals breaking into three power substations operated by Tacoma Public Utilities and Puget Sound Energy (PSU) and damaging the stations' electrical equipment, according to a Pierce County Sheriff's Department statement.

According to an update, more residences lost electricity after a fourth substation was attacked and a fire started in the area on Sunday night.

“It is unknown if there are any motives or if this was a coordinated attack on the power systems,” the Sheriff’s department said.

The first three incidences were referred to by the sheriff's office as "burglaries," but it was made clear that nothing had been taken from the electrical facilities.

In addition, the department stated that it had only begun its "initial investigation" into the attacks and that no suspects had been apprehended.

“All law enforcement agencies in the county have been notified of the incidents and will be monitoring power substations in their area,” the police said.

According to The Seattle Times, two PSU power stations in Washington state were attacked in November, which prompted the FBI to start looking into the incidents.

The bureau has received reports of similar incidents at electrical substations in Oregon and North Carolina, and Washington law enforcement has received an FBI document alerting them about such assaults.

With the exception of 900 customers, Tacoma Public Utilities declared Sunday evening that electricity had been restored to everybody.

The memo read:

"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."

Two accidents happened at their stations in late November, according to Puget Sound Energy, one of the biggest power companies in the state, which spoke with KING 5 on Wednesday.

"We are aware of recent threats on power systems across the country and take these very seriously. We are monitoring our infrastructure and can confirm we have had two incidents occur in late November at two different substations. Both incidents are under investigation by the FBI," said a representative of PSE.