The police are questioning a number of people in connection with the vandalism at a Cospicua sub-station two-days ago, a police spokesman has confirmed.
The vandalism caused a power surge to homes at San Gwann t-Ghuxa housing estate, burning electrical appliances.
The surge also caused a bedroom to catch fire. No one was injured.
Residents have been filing their claims for damages at Cospicua police station.