Schools will be closed on Monday in North Carolina’s Moore County due to power outage|Ian Muttoo|CC BY-SA 2.0

Several thousand residents in North Carolina’s Moore County were without power over the weekend after two electric substations were attacked on Saturday. Authorities are calling it a “targeted attack.”

Gunfire at the substations and the subsequent power outage led to a curfew on Sunday night. Schools would remain closed on Monday.

The motive behind the attack is not clear, per the county sheriff. The incidents were being investigated by local, state and federal law enforcement agencies.