A student picks up a delivery from a robot courier at Renmin University in Beijing on June 18.

One of China's biggest online marketplaces, has launched its first robot couriers.

The vehicles follow optimal routes based on calculation, and send messages to recipients five minutes before reaching the destinations. The recipients obtain the packages with facial recognition or by inputting a code.

The robot couriers, equipped with laser radars and cameras, are capable of avoiding obstacles on routes and recognizing traffic lights. With different sizes, they move three to four km/hour and can deliver six to 20 items in one trip.