Nigeria's national grid suffered a partial collapse on Tuesday, the state power transmitter said, marking the ninth incident this year to have caused power outages across the country.

The Transmission Company of Nigeria (TCN) said the grid experienced a disturbance at around 1252 GMT, triggered by a series of line and generator trips destabilising the system.

While some regions, including the capital Abuja, regained power about an hour after the collapse, outages continued elsewhere.

"TCN engineers are already working to quickly restore bulk power supply to the states affected by the partial disturbance," spokesperson Ndidi Mbah said.

Blackouts are frequent in Nigeria, Africa's most populous country with over 200-million people, due to ageing power infrastructure, vandalism and inadequate gas supply for its thermal plants, which account for over 75% of output.

Although Nigeria has the infrastructure to generate about 13 000 megawatts of power, its creaking grid can only distribute a third of it, forcing businesses and households to run costly fuel generators.