Image copyright Lake Kivu Challenge Image caption Rwanda is an attractive market for drone companies

Death comes fast, says Temie Giwa-Tubosun, as we sit in the scorching sunshine of Rwanda's capital Kigali.

She's talking about post-partum haemorrhage - women bleeding after childbirth.

"I'm always amazed that more attention isn't paid to this - it's the biggest cause of death in childbirth".

Temie's company, Lifebank, delivers life-saving blood to hospitals in her home country of Nigeria, and elsewhere on the continent.

Usually the blood is transported by road or on boats, but in Ethiopia some is moved by drone.

Mr Giwa-Tubosun is visiting Kigali for the first ever African Drone Forum at the shiny convention centre, which looks like a giant beehive crossed with a helter-skelter.

Image copyright Lifebank Image caption Temie Giwa-Tubosun is from Lifebank which would like to expand drone deliveries

It glows like a rainbow at night, and is the jewel in the crown of modern Kigali, the fast-changing capital of a country which Rwanda's politicians time and again tell us is open for business.

Technology is front and centre of the government's plan to become a higher-middle-income country by 2050. It's an ambitious goal, given over 35% of the population lives in poverty, according to government statistics.

But it's one which President Paul Kagame is clearly keen to push. As he stands in front of the audience, he says that drones will become not just part of the Rwandan skies - he wants them manufactured and piloted by Rwandans.

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Schoolchildren watching hop up and down with excitement, hands shoot into the air when speakers talk about drone networks. "I want to be a drone pilot," one girl, who can't be more than twelve, announces confidently. This is now one of the coolest jobs in Rwanda.

"In underdeveloped countries like Rwanda technology has to be adopted faster," says one college student called Benjamin. His classmate nods, she's studying engineering too. "People don't know about drones, but the young can tell the older generation" he adds.

Image caption Rwandan hills are slow to traverse

Rwanda, the country of a thousand hills and slow, tediously winding roads, was the first in the world to embrace a commercial delivery service by drone when Silicon Valley firm Zipline began flying blood in 2016.

It received a huge amount of global publicity and has delivered tens of thousands of units of blood. But Zipline is an exception. Its flights are classified as government flights, meaning it has high-level exemptions when it comes to air traffic management.

It's the thorny issue of regulation and management of the lower airspace which all agree is key to the establishment of sustainable long-term drone delivery networks.

Why drone deliveries?

Temie explains how her drivers have to learn the location of 400 hospitals by heart as the maps aren't accurate enough in a frantically urbanising city like Lagos, which is also clogged by traffic.

Drones for her are just a way to get what's needed to patients faster. But, in Nigeria, they're not yet used for drops.

"The regulation isn't there yet," she says, but she and most people here believe that this will change, and that African skies, which are less congested than many parts of the world, will lead the way. But can it happen as quickly as many seem impatient to see, and should it?

Freddie Mbuya, who owns the Tanzanian technology firm Uhurulabs, is a self-confessed nay-sayer.

"I don't think that delivery drones in Africa will be realistic in any meaningful way for the next decade. There's humanitarian need but no market opportunity."

Image copyright AFrican Drone Forum Image caption Freddie Mbuya believes cargo drone networks are some way away

"It exists now because of donor money and sponsorship."

For him, and his company, drones for mapping, and land surveying for clients such as miners are the most compelling use case.

The World Bank's Edward Anderson, who has focused on drones in the region, argues that they should be regarded as useful not just for medical deliveries.

"Rwanda is one of the most densely populated rural parts of the world. In the long run we're looking at drones providing economic opportunity in agriculture, for small-scale manufacturers, and to deliver time-sensitive goods such as cash and documents."

Image copyright Lake Kivu Challenge Image caption Drones have competed for contracts in Rwanda

Leapfrogging slow roads

A 90km drive from Kigali, taking over four-and-a-half stomach-churning hours, we arrive at a temporary drone port in a stunning spot by a bay of Lake Kivu, close to the border with the Democratic Republic of Congo.

Rwanda's rural areas are densely populated, but road infrastructure is inadequate. Most people walk miles up steep, high-sided hills, and the main road out of Kigali has a constant stream of foot traffic.

The lake is quiet, and still. A local fisherman tells us that's because of strict restrictions due to the neighbouring country's ongoing Ebola outbreak.

"The army says no," he says bluntly when we ask why there are so few boats, which would be a lot faster than roads to transport goods.

Image copyright Lake Kivu Challenge Image caption Many of the companies competing were from Europe

This is the Lake Kivu Challenge, the competition portion of the drone forum, and teams from around the world, mainly from Europe, are competing for contracts with the Rwandan government.

In a shed next to the hut where the little drones sit ready for their turn, we see mock-ups of blood transfusion bags and medical samples.

These will be picked up by the drones, dropped at a nearby island, then collected again within a certain time limit.

Sheltering in the shade we chat to Selina Herzog from German drone firm Wingcopter. It received a lot of attention last year for its vaccine drops on a remote island in Vanuatu in the Pacific. "We have to make sure we aren't just coming into a country, running a short trial, then leaving again," she says.

Image copyright Lake Kivu Challenge Image caption The drones had to drop and collect mock blood supplies from an island

Who will pay for the drones?

This has been one of the biggest criticisms of cargo drone experiments, funded more often than not by humanitarian agencies for a very short duration.

"We're not there yet with regulators, countries have different rules, we have a lot to work out still.... and the question is, just who is going to pay for this?" Ms Herzog asks.

This is something Lifebank's Temie Giwa is also passionate about.

"We have a moral responsibility to be cost-effective. We can't charge a developing country $250 (£204) for a drone delivery. [However] the only way to be sustainable is to be profitable."

Back in Kigali, Temie remembers her own emergency caesarean, while she was in the US.

She believes the outcome could have been tragically different if she'd been back home in Nigeria, as it is for so many women.

"I get tearful every time I think about this, it is so solvable."