Faults in Enemalta's Paceville distribution centre caused smoke damage and led to power and water cuts in the area.
Firefighters and ambulances were seen attending the scene on Monday evening as members of the public complained about power cuts in the St Julian's area.
The power cut also affected water supply systems in Gżira, Msida, Pembroke, Sliema, St Julian's and Swieqi.
A spokesman for the electricity provider said "faults" had developed at the centre "which caused smoke damage that was immediately controlled."
He said: "Due to the damage developed in the Distribution Center, as a means of security and precaution to carry out the necessary repairs, there was a temporary disruption in the electricity supply in the Paceville area."
Enemalta later posted on its Facebook page that it expected the "majority" of its customers to have electricity restored by 10pm.
A Water Services Corporation spokesman said that the company had diverted water to affected areas from other parts of its network as it brought systems back online.
"People in these areas may have experienced reduced water pressure but water levels are rising and normal service should resume shortly," the spokesman said at 6.40pm.
Enemalta said it was making "every possible effort to limit any inconvenience" caused by the repairs.