China has suspended most flights from the United States to Shanghai due to a rise in the number of inbound travelers carrying Covid-19, according to the government-published Shanghai Daily.

According to the newspaper’s website, five flights to Shanghai operated by Delta, United, and American Airlines, as well as one operated by China Eastern Airlines, will be suspended for two to four weeks beginning next week.

Since the end of 2021, more than 50 travelers on these flights have tested positive at Shanghai Pudong International Airport, the city’s key international airport, according to the daily, citing China’s Civil Aviation Administration.

Six travelers on Delta Air Lines Trip DL287 from Seattle to Shanghai tested positive on January 1, and another 11 on the same flight tested positive on January 6, according to Shanghai Daily. After 10 passengers tested positive on arrival at Pudong Airport on December 31, American Airlines Flight AA127 would be delayed for four weeks beginning January 24.

In addition, the publication reported that China Eastern Airlines’ MU588 flight from New York to Shanghai and United Airlines’ UA857 flight from San Francisco to Shanghai will be delayed for two weeks starting next week. The suspension comes just in time for the Chinese New Year holiday and the opening of the Beijing Olympics.