Senegal was hit by a nationwide electricity outage on Thursday following an accident at a power station in the capital, Senegal's power utility Senelec said in a statement.

The U.S. has committed over half a billion dollars in recent years to upgrade Senegal's electricity grid as part of a 2018 deal to improve access to reliable power.

The accident at the 90,000-volt Hann station triggered a wider outage on an interconnection grid, disrupting electricity distribution across the country, Senelec said.

It did not give any further details about the accident.

Since a severe power crisis a decade ago that crippled businesses and led to violent riots, Senegal has carried out reforms and invested heavily in generation and transmission to improve power supply.

In 2018, the U.S. signed a deal to give Senegal $550 million to improve access to reliable and affordable electricity. The government agreed to commit $50 million to the $600 million program.

The outage reflected the ongoing power troubles facing the West African nation. A U.S. embassy spokeswoman in Senegal did not respond to a request for comment on the outage.

The utility said in a statement to Reuters that power was gradually being restored to some regions, and parts of the capital, Dakar.