A team of drone operators joined climbers and guides at Everest Base Camp this climbing season, armed with heavy-duty drones to help clear rubbish from the world's highest peak.

Tons of trash—from empty cans and gas canisters, to bottles, plastic and discarded climbing gear—have earned once-pristine Everest the grim nickname of the "highest dumpster in the world."

Two DJI FC 30 heavy-lifter drones were flown to Camp 1 at 6,065 meters (19,900 feet), where they airlifted 300 kilograms (660 pounds) of trash down during the spring climbing season, which usually lasts from April to early June.

"The only options were helicopters and manpower, with no option in between," said Raj Bikram Maharjan, of Nepal-based Airlift Technology, which developed the project.

"So, as a solution for this problem, we came up with a concept of using our heavy-lift drone to carry garbage."

After a successful pilot on Everest last year, the company tested the system on nearby Mount Ama Dablam, where it removed 641 kilos of waste.

"This is a revolutionary drive in the mountains to make it cleaner and safer," said Tashi Lhamu Sherpa, vice chairman of the Khumbu Pasang Lhamu rural municipality, which oversees the Everest area.