A new electrical blackout, the fifth in less than a month, occurred in Cuba today as the country faces a very serious energy crisis, authorities said.

“There has been a complete disconnection of the Electrical System, the SEN, which may be related to an unexpected shutdown of the Antonio Guiterra thermoelectric plant, in the center of the island, but the causes are still under investigation,” the Ministry of Energy and Mines said.

According to the grid management service, the blackout occurred at 9.14am (16.14 GMT). The ministry assured that the process of restoring the fault has already begun.

Even before today’s blackout, many areas of the island were experiencing daily power outages of up to 16 hours.

Cuba’s power generation and distribution system is outdated while the country is plagued by fuel shortages, natural disasters and an economic crisis. Oil-fired power plants, which are antiquated and run on oil, are struggling to keep the lights on even though they reached their limits last year when oil imports from Venezuela, Russia and Mexico declined.