A major fault on Ghana's national power grid has triggered widespread outages, leaving the capital, Accra, the commercial hub of Kumasi and much of north without electricity.
Several power plants across the West African nation were forced to shut down in the early hours of Wednesday morning, the state-run power distribution company said.
"Our engineers and system operators are working continuously to restore power in the shortest time possible without compromising safety," Ghana Grid Company Limited (GRIDCo) has said in its statement.
Ghana has had regular power shortages for years - popularly known as "dumsor", meaning "on and off" in the Akan language - but the situation has been improving.
Wednesday's power cut has left homes, businesses and essential services without electricity across multiple regions of the country.
Many commuters had problems getting to work as those whose phones were not charged had difficulty paying for transport - and in some cases ordering taxis via apps such as Uber.
It has also affected small businesses and people relying on digital services, though big institutions, such as hospitals, tend to have back-up generators.
GRIDCo said it was conducting a comprehensive technical investigation to determine the outage's cause.
It did not say how long it would take for normal supplies to resume.
Ghana, one of the world's biggest producers of both gold and cocoa, has in recent years started using gas to generate electricity to help with demand as the population grows and becomes more urbanised.
Most of the country's electricity is generated by ageing hydropower plants, which have suffered from poor maintenance over years.
The addition of gas has eased power cuts, but the sector remains vulnerable to transmission failures and fuel supply interruptions.
