China's civil aviation regulator said on Wednesday that it has suspended three Shanghai-bound international air routes due to certain passengers on their recent flights having tested positive for COVID-19.

The Civil Aviation Administration of China said in a statement that it suspended an Etihad Airways route from Abu Dhabi and a China Eastern Airlines route from Manila for one week, as well as a Sri Lankan Airlines route from Colombo for four weeks.

A total of six passengers on the Aug 3 flight from Abu Dhabi tested positive for the coronavirus, as well as six passengers on the Aug 5 flight from Manila and 23 passengers on the Aug 7 flight from Colombo, meeting the conditions for a "circuit breaker" suspension of the flight route, it added.

In keeping with an international flights adjustment policy announced in early June, the administration issued its "circuit-breaker" directive and announced the suspension of the three routes would begin on Aug 17.

The administration also noted that the three carriers can still operate their flights before the order takes effect. But the time of the suspension will be extended if more passengers test positive for coronavirus.

On June 4, China eased restrictions on international passenger flights contingent on epidemic risks being under control. Authorities highlighted the "reward and circuit breaker mechanism" for the carriers to increase or have flights suspended in accordance with the companies' epidemic control work.

Under the policy, airlines must suspend flights on a route for a week if five passengers test positive for coronavirus. If the number exceeds 10, the airline must suspend the flights for four weeks.

As an incentive, carriers may increase the number of international flights to two per week on a route if for three consecutive weeks no passengers test positive for the virus in nucleic acid tests.