Another video has surfaced of a drone saving a life in China, where a man had to ditch his initial mission when he noticed a neighbour stranded on a roof during a flood.

Lai Zhongxin told local media that he was transporting the belongings of villagers displaced by flooding when he spotted his neighbour on a roof.

He used what looks like a DJI Agras drone with the container removed, to lift the man and move him to safety, the operator told a state broadcaster.

The video, which was widely circulated on social media, showed an area in the Guangxi region, in southern China, flooded with green-grey water, and a man dangling from a long cord attached to the drone, which set him down on a road.

It was through sheer luck that Zhongxin was there at all, using the drone for a radically different task from what he normally uses it for. He said he normally uses his UAVs to spray fertiliser and transport construction materials.

Drones have been used in south and southwestern China to provide aid to areas hit by torrential rains this past week. Hoisting large canvas bags filled with relief supplies, they flew over pools of floodwater and traffic-clogged roads, as extreme weather set off mass evacuations and emergency alerts. The drones also sprayed disinfectant on silt-covered fields.

Louis Liu, the founder and chief executive of DAP Technologies, a Beijing-based consultancy specialising in air mobility, compared the rescue of the man to an excavator being used to lift someone in a fire in the absence of other tools.

“Normally, people aren’t allowed to use an agricultural drone to suspend a person in midair,” he said.

“But in an emergency, if someone is about to drown, that’s something the law would overlook. Developing drones specifically for rescuing people is definitely an area for development,” he added. “Many in the industry are already attempting it.”

In the past week, firefighters in the southern city of Shenzhen carried out a drill using drones that flew up and down a glass skyscraper, spraying jets of water.

Drones are already commonly used in cities like Shenzhen for delivering takeout food and packages. In March, China’s Civil Aviation Administration issued approvals that would allow two companies, EHang and Hefei Hey Airlines, to operate drones for commercial passenger services.

The role of drones has become more visible since last year, when Premier Li Qiang identified the “low-altitude economy,” referring to the use of this technology in airspace under 1,000 meters, as a national priority.