(Reuters)--Japan's e-commerce giant Rakuten on Monday (April 25) unveiled what it called the first commercial drone delivery service in the world.

At the media preview, dozens of reporters gathered at a golf course near Tokyo to watch a drone drop off a package containing a bottle of water, golf balls and a hamburger.

"I believe this is the first commercial use of a drone. You can order the service on a smartphone, and your order will be delivered to you on the golf course," Chief Executive Officer of Rakuten Inc, Hiroshi Mikitani, said.

The service, called "Soraku', is exclusively for use on golf courses for now -- Rakuten hopes to work through legal restrictions in other areas and eventually expand its services.

"There are over 3,000 golf courses in the country and I think that's a big market. By sharpening the technology and operations here, we want to develop it for everyday use such as shopping as well," he added.

The service will begin in early May at the Camel Golf Resort in Chiba prefecture.

The drone can carry up to 2 kilograms (4.4 lb) of weight and takes off from within the golf course.

The Japanese government revised regulations in April to tighten laws governing drone flights over residential areas and city centres, but also allowed for commercial drone usage by certified professionals in certain circumstances and over private properties.

"Soraku," meaning "easy sky," and was developed by Rakuten and Japanese drone manufacturer Autonomous Control Systems Laboratory Limited (ACSL).