Fast Retailing Co. began selling Friday its washable and fast-drying face masks at its Uniqlo stores in Japan amid concerns about the novel coronavirus, with shoppers forming long queues.

The masks, which are sold in a pack of three, are made of the same material as its Airism underwear products, and are available in three sizes -- small, medium and large. Due to massive demand following the product's debut, customers were having trouble accessing the online shopping site of the operator of Uniqlo casual clothing store chain.

Numbered tickets were distributed at its store in the upscale Ginza shopping district to purchase the masks, which cost 990 yen ($9.3) for the three-pack, but by noon, masks for the day were sold out.

People form a long queue at a Uniqlo store in Tokyo's Ginza district on June 19, 2020. (Kyodo)

In a post as of 1:30 p.m., Uniqlo Japan's website said it had also run out of masks to be sold online.

"We are continuously beefing up production and will sell them as soon as they arrive," said Uniqlo on its website.

Overseas users will not be able to shop at the Uniqlo Japan online store, according to a Fast Retailing spokeswoman.

The company said the masks are limited to Japan for now but they plan to offer them at Uniqlo stores overseas.

According to the retailer, the new mask, which has three-layers and includes a filter, is able to maintain its basic efficacy even after being washed 20 times.

Purchases are limited to one pack per size per person, and the company plans on manufacturing 500,000 packs a week, it said.

Uniqlo's Airism mask (Supplied photo)(Kyodo)