Taiwan's military said one of its drones was missing and believed to have crashed on Wednesday, the first such incident since the sophisticated pilotless aircraft was introduced two years ago.

Ground crew lost track of the drone around 15 minutes after it took off from a base in east Taiwan's Taitung county early in the day, defence ministry spokesman David Lo said, declining to provide details of the mission it was on.

The drone, developed by the Chung Shan Institute of Science and Technology, Taiwan's main arms research unit, is designed to cruise for up to eight hours, with missions including surveillance and relaying communication signals.