A "major" power outage - on top of stage 4 load-shedding - left a large swathe of northern Johannesburg without electricity on Monday.

"A high-voltage Eskom power line feeding most City Power substations in the north of Johannesburg has tripped, causing a major outage in the northern areas, including parts of Midrand," tweeted City Power, adding that technicians were attending to the outage.

Some of the affected suburbs include:

• Strydom Park;
• Bromhof;
• Ferndale;
• Kensington B;
• Bryanston;
• Bordeaux;
• Beverley Gardens;
• Windsor;
• Cresta;
• Linden;
• Kelland;
• Blairgowrie;
• Randparkridge;
• Malanshof;
• Robindale;
• Fountainbleau; and
• Noordwyk.