China's air regulator moved Thursday to further cut international flights in a bid to prevent more imported COVID-19 cases coming to the country.

The Civil Aviation Administration of China said on Thursday that each Chinese carrier could only fly one route to another country, and one flight per week. Also, a foreign airliner could only fly one route to China, also one flight per week.

This is the latest tightening move taken by China to restrict the number of international flights, as more airports and airlines in the country have announced they will suspend international transfers or flights.

More airports and airlines in China have announced they will suspend international transfers or flights to prevent further imported COVID-19 cases, as China now faces rising numbers of imported cases as more countries are hit by the virus.

From Thursday, East China's Jiangxi Province suspended all inbound and outbound international flights. Jiangxi has only two cities that operate such flights - its capital Nanchang and the city of Ganzhou. The suspension will last for 14 days.

The suspension announcements came after 15 passengers on a Wednesday flight from Sihanoukville, Cambodia to Nanchang, Jiangxi Province were found to have fever, cough, diarrhea and other ailments.

In addition to Jiangxi, more airlines and airports have suspended international flights.

China Eastern said late on Wednesday that it will cancel some flights from China to Europe, the U.S. and Australia, with cancellations extending to May in some cases.

Shanghai Hongqiao International Airport on Wednesday suspended all inbound and outbound international flight services. The airport in Jinjiang, East China's Fujian Province has cut all its 17 overseas routes. An airport in Southwest China's Sichuan Province now sees fewer than 10 flights per day, down from 60.

China has witnessed a sharp decline of airports accepting overseas flights in recent days.

On Wednesday, China still had 23 airports able to accept flights from overseas countries and regions, compared with 34 airports on March 1, data from industry information provider VariFlight showed.

In detail, on Wednesday, Shanghai Pudong International Airport ranked the first, accepting 51 overseas flights, followed by 18 flights to Guangzhou, 10 flights to Beijing, and seven flights to Xiamen in East China's Fujian Province.

But the top three airports were Shanghai at 52, Beijing at 25 and Guangzhou at 18 at the beginning of this month.

"The suspension of transfers and fights could divert pressure on those big hubs such as Beijing, Shanghai and Guangzhou, and it could help stop the virus spreading to more cities in China," Zheng Hongfeng, CEO of VariFlight told the Global Times.

Some carriers have also announced they will suspend transfer services.

Air China said on Thursday that it will suspend small animal transportation services on international and regional flights to the Chinese mainland, and will also suspend international transfers from Beijing. As early as Sunday, China Southern Airlines said it would suspend transfer services.

China reported 67 new coronavirus cases on Wednesday. All were from overseas countries and regions, and Shanghai was the city with largest number of 18 cases.

Starting from 6 pm Thursday, a 14-day quarantine health observation will be implemented for all persons from overseas countries and regions entering Shanghai, according to local officials.

Starting Monday, all international flights to Beijing must first divert to one of 12 Chinese cities before they are allowed to enter the capital, China's air regulator said.