NAIROBI, Kenya (AP) — A nationwide power blackout hit Kenya Sunday evening, paralyzing large parts of the country, including the main airport in the capital, Nairobi, a major transport hub connecting East Africa to Asia, Europe and other parts of the world.

Sunday’s outage began around 8 p.m. local time (1700 GMT) and was the third national power supply failure within the last three months.

Among the key establishments affected was the Jomo Kenyatta International Airport in Nairobi, as well as Eldoret Airport in western Kenya, where emergency power generators failed to kick in after the power grid failed.

The state-run utility, Kenya Power, blamed the the blackout on a “system disturbance” which it claimed was being addressed by technicians.

“We have lost electricity supply to various parts of the country due to a suspected fault affecting the power system,” a statement said.

“We are working to restore normalcy within the shortest time possible. An update on the restoration progress will be issued in due course. We apologize to our customers for the inconvenience caused.”

Kenya Power enjoys a monopoly in the supply and distribution of electricity, but has for years been accused of poor service delivery and corruption that has led to the high cost of electricity in Kenya.

Some parts of the country reported the power had come back two hours later.

During a similar blackout last month, it took over engineers over 12 hours to restore power in most parts of the country.

But the worst outage was on Aug. 25, the longest disruption in Kenya’s history. The cause remains a mystery with the power company blaming a failure at Africa’s largest wind farm, which laid the responsibility on the power grid instead.

In parts of the country, including Nairobi, it took almost 24 hours for the power to come back on.

Kenyans on social media demanded answers from Kenya Power over the frequent power outages following Sunday’s failure, while others mocked the agency, saying it was worse than power companies in Nigeria and South Africa, where rationing or load-shedding, as it is known, is commonplace.

The latest blackout in Kenya comes at a time when the country is facing high fuel prices which many have blamed for millions of dollars in losses to businesses and the wider economy, which is struggling badly.