(Reuters) -Thousands of residents were without power near Tacoma, Washington, after three electrical substations were vandalized, local authorities said on Sunday, adding that it was not yet clear if the Christmas Day incidents were linked.
The Pierce County Sheriff's Department said robberies were reported at two substations belonging to Tacoma Public Utilities and another belonging to Puget Sound Energy. Deputies cited forced entry into the fenced-in area, with equipment vandalized but nothing taken from the sites, it said. More than 14,000 customers were affected.
"At this time deputies are conducting the initial investigation. We do not have any suspects in custody. It is unknown if there are any motives or if this was a coordinated attack on the power systems," the department said in a statement on its website.
Earlier this month, a utility in North Carolina reported outages from what local authorities said were orchestrated shootings now being investigated by federal law enforcement.
The FBI has also been investigating shots fired near a power facility in South Carolina days later, and whether those two incidents could be related, NBC News and other local media have reported.
Utilities nationwide have been strained by a severe cold weather system that swept across the country this week, leaving more than 300,000 without power from the winter storm.
In east Piece County, about 2,700 people serviced by Tacoma Public Utilities remained affected midday on Sunday after an initial 7,300 residents lost power in the area, about 45 miles (72 km) south of Seattle, Tacoma Public Utilities said in a post on Twitter.
"We are working as quickly and safely as possible to restore power," it said, noting that its substations "were attacked" earlier on Sunday morning and that the incidents were reported to police.
Representatives for Puget Sound Energy could not be immediately reached for comment.