The incident at the centre of a murder charge against Cuba's former president, Raúl Castro, is burned into the collective memory of both Havana and Miami.

The US case, unveiled on Wednesday, accuses Castro and five others in the shooting down of two planes belonging to Cuban-American group Brothers to the Rescue in 1966 - killing four people, including three Americans.

Cuban President Miguel Díaz-Canel has called this and other charges levelled at Castro "a political manoeuvre, devoid of any legal foundation".

US Secretary of State Marco Rubio has since said Cuba poses a "national security threat" and the likelihood of a peaceful agreement between the two countries is "not high".

As the charges against Raúl Castro were announced, many Cubans were unaware and incommunicado due to the 20-hour blackouts continuing to grip the island. The US has imposed a near-total fuel blockade that has affected almost every facet of daily life.

US President Donald Trump has repeatedly sought to exert pressure on Cuba and has openly discussed toppling its communist regime.

The US has demanded political and economic reforms but the specifics are unclear beyond a leadership change. They could include a pledge to open up the economy to more foreign investment and a commitment to end the presence of Russian or Chinese intelligence agencies on the island.

Ana Rosa Romero lives on the 11th floor of the Granma Dos building, an imposing modernist social housing block in the Cuban capital, Havana. A widow in her 70s, she said that when her husband died recently, a blackout in her neighbourhood meant she had to sit with his body for hours before it could be moved.

These days, with the lift so often not working, she says she barely leaves her apartment.

"You can hardly go out," said the former philosophy teacher, a framed picture of Fidel Castro on her wall.

"If you do venture out, it's with the uncertainty of not knowing what's coming next. When is the power due to go out? When is it coming back? How many hours are we going to be without electricity?"

It is a risk to find herself at the bottom of the stairs at her age with eleven flights to climb with bags of shopping, Ana Rosa says. But others in the building are worse off.

The building's superintendent, Juana Garcia, says nine residents have pacemakers and simply can't take the chance of being caught without the lift. Others have been trapped inside the elevator mid-blackout for hours.

Juana has spent almost six months trying to pump water to more than 100 residents with no electricity. Some elderly residents are bedridden and get no water unless a neighbour carries it up several flights in the dark.

"It's dangerous to go up and down these stairs without lights. This is a such a difficult situation. We know we're going through tough times, but it's sad to see this great building stuck in the darkness," she laments.

Her hope is the state can provide solar panels to bring some respite to her residents, particularly the most vulnerable.

In another part of Havana, Barrio Toledo, a new form of social housing is under construction.

Around 40 disused shipping containers are being repurposed into two-bedroom homes, with a kitchen and a bathroom. Around a dozen are close to completion while others sit with the logos of the shipping companies still visible on the outside, rudimentary windows cut out of the sides.

None are yet inhabited as the Cuban state tries to carry out a plan amid the fuel shortages for a small community of container houses around a children's playground and a local store.

Critics say the heat inside the metal homes will be unbearable in the height of Cuba's summer. But the site's foreman, a committed revolutionary called Orlando Diaz, insists they are a well-ventilated, smart solution to the capital's acute housing crisis.

"This technique is already being used successfully in other countries," he says. "We're just catching up."

Diaz says he and all the workers at the site will take part in a government-organised march on Friday in defence of Raúl Castro over the US murder charges.

I ask him if he thinks the indictment was a precursor to military action.

"The charges against Raúl are a vile lie," he says, echoing the government line.

"Why did they bring charges against him but not against Luis Posada Carriles," he added, referring to the late Cuban American militant whom Cuba accused of masterminding the bombing of an airliner in 1973, which killed 73 people.

Diaz is well aware of what happened in Venezuela in early January when Nicolás Maduro was forcibly removed from power by US troops. But he is convinced that if the Trump administration is building towards the use of force in Cuba, the outcome will be very different.

"Venezuela is Venezuela, but Cuba is Cuba," he said defiantly. "And here we don't lack the necessary courage to face this moment."

Back at her 11th-floor apartment, Ana Rosa Romero looks out from her balcony, across the Estadio Latinoamericano baseball stadium, where a decade earlier she looked down and saw Barack Obama and Raúl Castro watch a game together.

Today, she is contemplating the prospect of US military action on her doorstep.

"At my age, I know I'm going to die in Cuba," she says matter-of-factly. "We've faced so many things over the years. And if now we have to face an invasion, then I guess we'll face that too." (BBC News)

Update news