The advance means drones could soon be used in parallel with rescue teams to accelerate the search for people lost in the wild, researchers said.

Every year, thousands of people lose their way in forests and mountain areas. Drones can effectively complement the work of rescue services teams, researchers cited.

Since they are inexpensive and can be rapidly deployed in large numbers, they substantially reduce the response time and the risk of injury to missing persons and rescue teams alike.

Researchers, including those from the Dalle Molle Institute for Artificial Intelligence and the University of Zurich developed a software that allows drones to autonomously detect and follow forest paths.

"While drones flying at high altitudes are already being used commercially, drones cannot yet fly autonomously in complex environments, such as dense forests," said Davide Scaramuzza from the University of Zurich.