From Benguela, a city on the west coast of Angola, it takes four hours to reach the village of Cabio by car, first on potholed highways and then on unmarked sandy tracks that take you deep into the bush. It is a remote place, and a poor one. Its 82 inhabitants live in tiny houses built of mud bricks and corrugated iron. Its open-air church is little more than an arrangement of sticks. Its school is a blackboard tacked to a tree.

For the newcomer, however, Cabio has a surprise up its sleeve. Though barely reachable by road, the village is a stop on the Benguela Railway, which runs from the port of Lobito in the west all the way to the Democratic Republic of the Congo in the east. The railway, which fell into disrepair during Angola’s brutal civil war, was reconstructed between 2006 and 2014 by the Chinese, and with it Cabio’s station. Flamingo pink, in the Portuguese style, it could not look more incongruous if it tried.

Thanks to its proximity to this railway, Cabio was strategically important during the war, and although there are no soldiers here now, its inhabitants still live with a legacy of those days. Next to the village, on a hill where livestock should be able to graze and children to play, is a minefield laid to protect a former army position (this point was held by the armed wing of the People’s Movement for the Liberation of Angola [MPLA], the party that now governs the country). It is the size of seven football pitches.

The mine-clearing women of Angola – in pictures Read more

During the worst of the fighting, Cabio was evacuated. When its people returned, no one told them what had happened to their land while they were away. “But our animals kept dying,” says Jose Palanga, the village chief. “That was how we knew.” In Angola, a cow can be worth up to $600; to lose one means the difference between a family eating and going hungry. “The minefield was destroying our lives,” he says. “We cried out for help. We begged for it.” None came.

As the years ticked by, the villagers could only be grateful that no human had yet stepped on a mine (anti-personnel mines of the kind buried here detonate easily; all it takes is a child playing with a stick).

But last January, the Halo Trust, the British landmine charity, set up camp in the village, bringing with it a small army of its own in the form of 18 Angolan women mine clearers. Having since removed 197 mines and 50 items of unexploded ordnance from the area, it hopes to complete the job next month – at which point the land will be returned to the villagers.

Facebook Twitter Pinterest Princess Diana walking in one of the safety corridors of the landmine fields of Huambo in 1997 and Prince Harry in Dirico last week. Photograph: Juda Ngwenya/Dominic Lipinski/Reuters

“You can’t imagine how happy we’ll be,” says Palanga. “We’ll be able to build. Perhaps more families will come here. Perhaps the village will get bigger.”

The mine clearers, who live on site for 24 days at a time, are part of 100 Women, a project that aims to empower those involved, as well as to clear mines. So far, 78 have been recruited. Most clear mines, but some work in other capacities: for instance, as cooks. For one in five, this is their first job. Many are single mothers; three-quarters have three or more dependents. The work brings with it a decent salary, and some will tell you happily that it has helped them to buy land, even to build a house.

But the gains are not only financial. Clearing mines is both extremely dangerous and of immense benefit to Angola, one of the most heavily mined countries in the world. The job brings with it a certain respect.

“When I heard they weren’t just recruiting men, I felt it was my duty to show that women could do this, too, by being one of them,” says Maria Niva, who at 19 is one of the youngest women at Cabio (Niva is one of those who met the Duke of Sussex when he visited a “transformed” Huambo last week, hoping to boost the anti-landmine campaign begun there by his mother, Princess Diana).

Wasn’t she frightened? “The first time I saw an explosion, yes, I was. But you get used to things.” She smiles. “A big change is coming to Angola. It will be safe at last, and that will be amazing.”

Her optimism is infectious. But the task ahead is huge. Angola’s civil war began in 1975. By the time it ended in 2002, more than 500,000 Angolans were dead, millions had been displaced, and its countryside, cities and roads were covered in mines.

Facebook Twitter Pinterest Maria Niva prepares her equipment before going to work. Photograph: Antonio Olmos/The Observer

How many mines are there in Angola? It’s impossible to say. The various factions left no maps. Halo, which has 381 staff here working in 28 operational teams, has so far cleared 100,000 landmines (75 different kinds of devices, manufactured in 22 different countries). In Cuito Cuanavale alone – the site, between August 1987 and March 1988, of the biggest battle in Africa since the second world war – it has cleared 35,000 mines. Across Angola, 1,100 known minefields remain, in which there may be up to 500,000 devices.

Could the country, a signatory of the 1997 Ottawa treaty, the convention banning landmines, meet its commitment to being mine-free by 2025? Only if the work, whose estimated cost is £214m, is fully funded by international donors such as the US and British governments. More money is needed. Alex Vines, the head of the Africa programme at Chatham House, has said that at the current rate of funding, Angola will not be mine-free until 2046.

The women at Cabio camp rise at five, put on their boots and uniforms, and line up outside their tents for registration, their faces still morning-soft as they respond to their names (I’ve spent the night in camp with them). Five minutes later, they and their protective gear are in the back of a truck, and moments after this they are by the railway line. Although highly trained – each one attended a month-long de-mining course – every shift begins with a demonstration of part of the process: a reminder of the ever-present dangers of the work ahead (these dangers are brought home to me when, before I join them, a note is made of my blood group). An ambulance also waits beside the railway line.

Facebook Twitter Pinterest Suzana Soares: “It’s wonderful to see the area we’ve cleared.” Photograph: Antonio Olmos/The Observer

After this, the sun now almost up, they spread out, each claiming a spot at the edge of land that has already been cleared. A whistle blows: a sign they should get ready to begin. When it sounds for a second time, they fall to their knees, moving their metal detectors over a small rectangle of earth they have first carefully marked out with red cord. If the detector makes no sound, they shuffle forwards, and repeat. Beside them is a bucket of tools: shears for tackling the brush; painted sticks to mark areas that have been cleared. In some places, Halo uses heavy machinery to clear mines. But Cabio’s isolation, and the lie of the land, make that impossible here. The job must be done by hand, inch by inch. It is intense work, and they do it in half-hour segments, a 10-minute break between each one.

“I like blowing the whistle,” says Suzana Soares, with a grin. Soares, who is 28, started as a cook, moved into mine clearing and is now a section commander. “It’s my responsibility to make sure they’re all safe; that they all take a break. It’s a big job, and I’ve been chosen from among all these girls.”

While she’s away, her sister looks after her small daughter. She misses her, and finds this hard. “It’s not a piece of cake,” she says. But it’s worth it. She is no longer dependent on her parents; she can give her child anything she needs. Like everyone here, her family was affected by the war. Now she has the chance to effect change in her country: “It’s wonderful to see the area we’ve cleared.”

There is a kind of feminism in the air. Esperança Ngando, who is 24, tells me she was compelled to apply for a job at Halo when the recruiter told her that her work would save people’s lives (she is another of those who met Harry in Huambo – though when I speak to her the week before his visit, she has no idea who he is). “Those words got to me,” she says. When she realised she would have to live in a tent in the bush for weeks at a time, she cried: she has a husband and three-year-old son. But she likes the life now. She has found solidarity here. “We’re happy together. It’s a family.”

Some days, the women find nothing. But on the morning of my visit, a mine is discovered – this makes them all very happy – and before I leave, it is detonated in a controlled blast. Watching such an explosion, you wonder how anyone who comes unexpectedly into contact with such a device could possibly survive. But survive they do, albeit with horrifying injuries. The 2014 census recorded 88,000 living victims of the explosive remnants of war (the real number is probably higher). Accidents, moreover, continue to happen even in areas that, officially, have been cleared.

Facebook Twitter Pinterest Manuel Rodriguez with his mother Ermelinda Victoria Jaime. Manuel lost one of his legs when a landmine exploded as he played with friends. Photograph: Antonio Olmos/The Observer

In Huambo, the next stop on my journey, only one uncleared mine field remains, and as a result, the city has grown hugely since Diana’s visit in 1997. Minefield H013, which she crossed in full protective kit, has been fully cleared since 2005, and is now, as her son found out when he walked in her footsteps last week, a busy street, thronged with people and traffic (in 1997, it was still semi-rural). All the same, a month ago, three children from the same family were killed by unexploded ordnance in the city.

Ten-year-old Manuel Rodriguez lives in San Antonio, a barrio once close to several of Huambo’s military bases. Three years ago, he and four of his cousins were playing with some stray mangoes on his grandfather’s land when one of them picked something up. In the explosion that followed, one boy, Frederico, died; Manuel and another cousin, Jeremiah, both lost part of their legs. Rescued by soldiers, he spent three weeks in hospital.

What was it like when he came home? “It was difficult at first,” he says, gazing down at his Liverpool shirt (he is a football fan). “I had to learn to use crutches. I used to fall down all the time.” If he is lucky, in the future he will be fitted for a prosthetic leg at Huambo’s orthopaedic centre, a hospital that was last week renamed in memory of Diana. But in Angola, nothing is guaranteed.

Others have been living with their injuries for decades. Nearby is the home of Luciana Baroso, a mother of eight. Baroso lost her sight in 1994, when she was nine, in an accident that killed her sister, Valentina. The two girls had been to nearby fields to get potatoes for lunch. Her sister hit a mine with a hoe, and it exploded. Somehow, Luciana managed to drag herself to the road; she was taken to hospital by a boy on his bicycle.

Facebook Twitter Pinterest Mother of eight Luciana Baroso, who lost her sight in a landmine explosion when she was nine. Photograph: Antonio Olmos/The Observer

“I hoped I would see again,” she says. “When I was discharged, no one told me that I wouldn’t.” How did she cope? What effect has the accident had on her life? “The trauma is still with me,” she says. “I can’t do ordinary things.” Tears roll down her face. “I feel it very badly.” In the doorway her mother, Maria, weeps silently.

It would be easy to feel hopeless, knowing the scale of the work that lies ahead. But everyone agrees that Diana’s visit here was transformational. It boosted funding and led, before the year was over, to the drafting of the Ottawa treaty, later to be signed by 133 countries. All those involved in mine clearance in Angola hope that Harry’s visit will have reminded public and private donors alike that what she campaigned for has not yet been fully achieved. Meanwhile, the Angolan government has recently signed a $60m agreement with Halo that will enable it to clear 135 minefields in the Mavinga and Luengue-Luiana national parks, land that includes the headwaters that feed the Okavango delta, one of Africa’s last wildernesses and home to thousands of threatened species. Harry visited the first minefield to be cleared as part of the project, at Dirico, last Friday.

Above all, there is the fact that 30 countries have been cleared of mines since 1997. Mozambique, another former Portuguese colony, was declared mine-free in 2015. “That took 22 years,” says Ralph Legg, Halo’s programme manager in Angola. “Even when the work involved seems overwhelming, there is no excuse. It can be done, and it must be.”