Police authorities have launched an investigation after unmanned aerial vehicles (UAVs) had been spotted hovering above prisons in southeast China, told the South China Morning Post.
"The devices were seen hovering or maneuvering above the jails' dormitories, teaching blocks, administrative buildings and residential quarters of armed prison police forces in Fuzhou, capital of Fujian Province," said the SCMP, quoting a report by the Strait Metropolis Daily.
The presence of drones at restricted areas has raised alarms over the likelihood of in-prison smuggling.
"The drone operators might intend to deliver dangerous goods to inmates or to take videos of correctional officers and facilities, which poses a grave security threat," the prosecutor's office of Gushan District was quoted as saying.
The authorities did not divulge specific details about the number and type of drones spotted.
Officials have advised involved prisons "to report sightings to local police and disrupt the drones' operational frequencies," said the Global Times, citing a Strait News report.
If drones were indeed used to smuggle goods, it would not be the first time.
In February, the BBC reported that the use of UAVs to smuggle contrabands into jails has been rampant.
Citing figures from the Press Association Freedom of Information, the BBC said that 35 sightings of drones "in or around prisons in England and Wales" have been recorded from 2014 to 2015.
"Across the 35 incidents, drugs were discovered at least six times, mobile phones more than eight times and a drone itself recovered in 19 instances," the BBC wrote.
"One of the biggest finds listed a drone, drugs, mobile phone, a charger and USB cards at HMP Oakwood in the West Midlands in December last year," the news agency added.
The issue of privacy and security of drones is not exclusive to China, which is now deemed as one of the biggest makers of UAVs.
The U.S. Federal Aviation Administration, for example, has received complaints against drones being too obtrusive, prompting the agency to require UAVs to remain under 500 feet and within sight of their operator.