Fifteen drones made in the U.S. today began transporting blood supplies to hard-to-reach parts of Rwanda in what’s being described as the world’s first commercial regular drone delivery service.

Engineers testing the drones in Rwanda prior to launch say they had an audience of locals every day at the distribution center, and the crowd cheered for every takeoff and landing, Fast CoExist reported.

But some aid workers say drones have a bad reputation in Africa. The public can’t distinguish between good ones and bad ones, according to BBC.

Zipline, the Silicon Valley startup responsible for the drones, is staffed by engineers who once worked at Space X, Google, Lockheed Martin and other tech companies, according to BBC.

Blood, plasma, and coagulants are the drones’ payload. They’re fired into the air using a catapult, and stay in the air, dropping their cargo using a biodegradable parachute to hospital personnel waiting below. Using drones to deliver blood reduces the wait time from hours to minutes at a cost roughly equal to the current delivery method by motorbike or ambulance.

Flying below 500 feet, the drones avoid the airspace used by passenger planes.They’ll be flying up to 93 miles, but could go further — up to 180 miles. They are battery-powered, weigh 28 pounds and can carry a cargo of about 3.3 pounds, or three bags of blood, Al Jazeera reported.

Zipline has been testing drone deliveries for months in Rwanda. The first distribution center opened today, Oct. 14, in Rwanda’s Muhanga District. It was built in California, then loaded on a giant UPS plane and flown over, Fast CoExist reported. The cargo containers that held all the components became part of the new base.

The center will make up to 150 deliveries a day to 21 health centers in western Rwanda. In early 2017, service will expand to eastern Rwanda. It’s expected to save thousands of lives—particularly new mothers at risk of dying from postpartum hemorrhage.

Locals are starting to call the drones “sky ambulances,” Fast CoExist reported.

Drones have already been used for humanitarian purposes elsewhere in Africa, including Madagascar and Uganda. Some aid workers say drones are not always appropriate, according to BBC:

“Whether we like it or not, UAVs (unmanned aerial vehicles) are confused with weaponized drones and are perceived by the general public as related to military operations and/or intelligence gathering,” a Congo-based worker said in a study by a Swiss foundation.

“In countries and contexts with conflict environment, it is illusory to imagine that the general public, authorities and the armed actors will make a distinction between good ‘humanitarian/civilian’ drones and bad ‘military’ drones.”

Rwanda has no plans to use drone technology for defense, the country’s information and communications technology minister said.

Security fears have held back drones elsewhere in Africa. A Swiss drone delivery project called Flying Donkey wanted to operate fixed-wing drones in northern Kenya to supplement postal services about three years ago. Authorities saw it as a threat to security and nixed it.

A conservation project using drones to monitor elephants also got shut down. Most governments in Africa have laws that ban or restrict drones, stifling innovation and losing investments that could create jobs, BBC reported:

While there are legitimate concerns about privacy and safety, the absence of progressive drone laws that also cater for innovation means African countries will continue missing out on the multi-billion dollar industry.

Using commercial drones to transport essential medical products is a milestone for Rwanda, President Paul Kagame said at the launch. Kagame has been nicknamed “The Digital President” for his commitment to leading a technology movement in Rwanda, World Bank reported.

“Technology becomes relevant and meaningful when it works for people and addresses challenges they face,” Kagame said at the launch.

The Zipline team tested the drone delivery system every day for months in Rwanda to make sure it works, usually with an audience of locals, Fast CoExist reported.

“Every day, we have hundreds of Rwandans lining up along the fence of the distribution center to watch operations,” said Keller Rinaudo, Zipline founder and CEO. “The whole crowd cheers for every single takeoff and landing throughout the day. Some people show up at 6 a.m. to get good seats.”

In addition to Rwanda, Mauritius and South Africa led the continent for regulations that allow for drone licensing and operation, according to BBC.

Kenya, Uganda and Morocco have banned or restricted drone operations.Drone operators in Ghana face up to 30 years in jail for failure to register their drones.

The majority of Rwanda, population 11 million, is poor and lives in rural areas that hard to reach. Roads are often washed out in a country known as the Land of a Thousand Hills.

“They know that the plane’s presence means that if a member of their family has a medical emergency, they’ll have access to the medical products they need to save their life,” Rinaudo said.

Zipline plans to begin delivering other medical supplies including medicine thanks to  a grant from the UPS Foundation, Fast CoExist reported. It also plans to expand service around the world including to remote areas of the U.S.