Nigeria has been hit by widespread power cuts following a “total system collapse”, electricity distribution companies say.
Levels of power being generated fell to zero megawatts early on Thursday.
Some supplies have been restored but only a tiny fraction of normal consumption in Africa’s most populous country.
Power supplies are often erratic in Nigeria, despite its role as a major oil and gas producer.
The West African country’s grid collapsed at least four times in 2022 – authorities blamed this on technical problems.
The theoretical maximum amount of energy Nigeria could produce is 12,500MW, but the country normally produces a quarter of that, the Reuters news agency reports.
On Thursday at around 10:30 local time (09:30 GMT) power levels rose from zero to 273MW, which is still well below the daily average of 4,100MW, data from the Transmission Company of Nigeria showed.
President Bola Tinubu, who has been in power for just over 100 days, has promised to improve supply by allowing state governments to build their own power plants.