Cuba has reported its second nationwide blackout in less than a week, plunging the island into darkness shortly before evening.

On Friday, the Union Electrica de Cuba, the state-owned utility that manages the electrical grid, announced the outage began at 4:30 p.m. local time. The utility provided no explanation for the blackout.

The failure follows a similar power outage on Monday, bringing the total number of island-wide blackouts to four since the start of 2026. Two other total blackouts occurred in March.

Cuba's electricity infrastructure is aging, with much of the system dating to the Cold War period between 1960 and 1980. But the problem has intensified since January, when U.S. President Donald Trump effectively cut off Cuba's supply of foreign oil.

On January 3, Trump authorized a military operation against Venezuelan President Nicolas Maduro, a socialist leader and ally of the Cuban government. Maduro was abducted and transported to New York, where he remains imprisoned on drug- and weapons-related charges.

Shortly after Maduro's removal, Trump announced that Venezuela would no longer send oil or money to Cuba. His administration has continued to control Venezuelan oil exports since then.

On January 29, Trump issued an executive order declaring that Cuba "constitutes an unusual and extraordinary threat" to the U.S. and threatened steep tariffs against any country that supplies the island with fuel.

According to the International Energy Agency, Cuba produces only 40 per cent of the oil it uses as of 2023. The rest comes from overseas. Since the fuel restrictions began, only a single Russian oil tanker has reached Cuba — in March.

Human rights experts have warned that continued fuel deprivation could harm Cuba's civilian population as public services like transportation shut down.

In June, Volker Turk, the high commissioner for human rights at the United Nations, said the fuel restrictions and tightened sanctions are "directly harming Cubans, especially the most vulnerable."

"Children are dying because doctors lack access to essential medical supplies and medicines," Turk said in a statement. He pointed to statistics showing infant mortality nearly doubled in recent months.

The Trump administration has blamed mismanagement by the Cuban government for the blackouts. U.S. Secretary of State Marco Rubio told Al Jazeera in March: "We've done nothing punitive against the Cuban regime."

Cuba has accelerated a shift toward renewable energy, with solar technology imported from China now accounting for about 18 per cent of the island's energy consumption as of 2022. The country aims to produce nearly a quarter of its energy from renewable sources by 2030.

Source: Al Jazeera