A drone patrols above a high way in Guangzhou, South China's Guangdong province, May 2, 2016. The traffic police used drones to help them patrol during the three-day May Day holiday.[Photo/Xinhua]

A 4-year-old girl in Northwest China's Shaanxi province missing for 77 hours finally was found, thanks to a drone, on Wednesday, according to Chinese Business View.

Police in Hancheng city found the girl in a deep ditch and said she suffered no serious injuries except for scratches and dehydration.

The girl, Xuanxuan, went missing from home in Macun village, Hancheng, at around 10 am on Sept 11. Her grandfather, surnamed Gao, called the police.

Gao said he got up at 6 am and went to the village committee while his granddaughter was still asleep. But when he came back, the girl was gone without her shoes.

People working in nearby fields told Gao they heard a child crying 10 minutes earlier, but the family found nothing except some children's footprints.

When searching for Xuanxuan, the police also heard what they suspected was a crying child, but they failed to locate the girl.

On Sept13, police found an inaccessible ditch and decided to use a drone to search it.

Xuanxuan was finally recovered in the ditch at?noon on Sept 14.

Police said the child's disappearance appears to be accidental and it likely happened when Xuanxuan woke up, found she was alone and tried to find her family.

The girl is now in a hospital and the case is still under investigation.

During recent years, drones have been used more often by police in their work.

Police in Nanjing, East China's Jiangsu province established a drone squadron last year. The squadron, consisting of seven drones, is responsible for city patrols, crowd monitoring at major events, chasing crime suspects and disaster relief.

The drones, equipped with HD cameras and 4G transmission technology, can reach a height of over 100 meters and fly about 20 minutes uninterrupted.

In June, police in Southwest China's Sichuan began to use drones to detect traffic violations, such as illegal parking and occupying emergency lanes. The drones also are used to monitor traffic jams to help direct traffic flow.