Customers select cosmetics at a duty-free shop in Haikou, South China's Hainan province, on July 12, 2020. [Photo/Xinhua]

Sales of offshore duty-free shops in China's island province of Hainan exceeded 5 billion yuan ($720 million) from July 1 to August 18, an increase of 250 percent year-on-year, local authorities said Wednesday.

Data showed some 740,000 customers visited Hainan's duty-free shops during the period, up 70 percent year-on-year.

Chen Xi, director of the provincial department of commerce, said the newly introduced duty-free goods were welcomed by customers, with mobile phones, liquor and tablets being the best-selling products.

Total sales of single products priced above 8,000 yuan reached nearly 1.2 billion yuan, surging by 420 percent year-on-year. "It has played an important role in winning back consumers who bought high-end products overseas," Chen said.

Starting on July 1, Hainan increased its annual tax-free shopping quota from 30,000 yuan to 100,000 yuan per person.

The range of duty-free goods has also expanded from 38 categories to 45, while the previous tax-free limit of 8,000 yuan for a single product has been lifted.

China released a master plan in early June on building the southern island province into a globally influential free trade port.