The number of foreign customers to South Korean duty-free stores dropped by 19.2 percent from 1.23 million in March to 998,000 last month, data by the Korea Duty Free Shops Association showed Tuesday.

The decline was largely due to a sharp decrease in Chinese visitors following Beijing‘s trip restriction in retaliation against Seoul’s hosting of a US missile defense program.

The April figure is also the lowest in nearly two years since the duty-free stores suffered a slump in light of the outbreak of the Middle East Respiratory Syndrome in the summer of 2015.

The comparative figure for Korean visitors, in the meantime, rose 6.8 percent on-month to 2.7 million in April.

The combined figure marked a decline of 1.7 percent on-month.

The total sales of the duty-free shops also reduced by 11.2 percent to $590 million in April from March, while the sales from locals increased 12 percent to $299 million.