China's popular resort island of Hainan recorded strong sales growth for its offshore duty-free shops during the week-long Spring Festival holiday that ended Sunday.

The four duty-free shops in the cities of Sanya, Haikou, and Qionghai sold 643,000 items between February 4 and 10, up 30.4 percent from the Spring Festival holiday last year, Haikou Customs announced Monday.

The sales value rose 33.6 percent to 601 million yuan (about 88.8 million U.S. dollars), the customs said. The number of buyers rose 23.2 percent to 122,000.

The duty-free goods sales hit a new daily record of 108 million yuan on February 8.

The robust sales came after authorities in the southern province increased the annual offshore duty-free shopping quota for both travelers and locals and added some home medical devices to the duty-free list from December.

Hainan also opened two new offshore duty-free shops in Haikou and Qionghai in mid-January, adding to the previous two in Haikou and Sanya.

The State Council gave Hainan permission to run a pilot offshore duty-free program in April 2011 in an effort to make the island a world-class tourist destination.

Duty-free sales in Hainan grew at an annual average rate of 39 percent between 2011 and 2018, with annual sales rising from 986 million yuan to 10.1 billion yuan.