(File photo)

Authorities at several prisons in Fuzhou, East China's Fujian Province, reportedly spotted drones hovering above the cellblocks late at night, sparking concern about security loopholes in drone management.

According to Fujian-based newspaper Strait News, a few prisons in Fuzhou saw some drones fly around and hover over cellblocks, teaching buildings and administration buildings, as well as over the positions of armed police stationed at the facility.

The report failed to give more details about the number or location of the prisons or the types of drones spotted, claiming that no explanation for the sightings has been found.

The People's Procuratorate of Gushan county, Fuzhou has advised the prisons to report sightings to local police and disrupt the drones' operational frequencies, Strait News reported Friday.

The procuratorate also pointed out that the presence of drones poses great risks to prisons by allowing possible deliveries of dangerous goods or allowing aerial surveillance of prison facilities, according to Strait News.

The use of drones in China has been on the rise in recent years, but national regulations on the drone industry and on drone flights in the country's restricted low-altitude airspace have yet to be announced.

At a forum in 2015, foreign and Chinese experts renewed their call for urgent implementation of specific regulations on the drone industry in China to avoid problems including invasions of privacy and terror attacks.

"The average drone can carry up to 1 kilogram. It could carry a camera, but it could also carry TNT or sulfuric acid," an aviation expert who requested anonymity told the Global Times previously.