More than 400 flights have been cancelled in China mid-July, and half of them recorded in eastern China airports this week alone due to air traffic restrictions that are expected to last until next month.

According to Shanghai Airport Authority, at least 101 flights were cancelled at Pudong International Airport and another 98 flights from Hongqiao International Airport last Monday.

Like Us on Facebook

The figures of cancelled flights were apart from 120 flights delayed by more than two hours in both airports on the same day, the Shanghai Daily reported.

Chinese officials have declined to elaborate the reason behind the mass flight cancellations. They only referred to the air traffic restriction imposed near Shanghai, which also affected flights in Nanjing and Hangzhou airports.

However, state television CCTV reported that the civil aviation authority requested airline companies to reduce its flights by 25 percent in the eastern part of China.

Speculations have surfaced on the internet that air traffic restrictions were imposed due to a military operation.

The government detained two people for allegedly spreading rumors that the restrictions were made because Chinese officials were trying to apprehend a high-ranking official who was fleeing the country, Shanghai Daily reported.

Authorities have also detained another 37 "rumormongers," it added.

The Monday's flight cancellation was part of a series of large-scale flight disruptions recorded in China following the postponement and cancellation of over 700 flights early this month due to typhoon "Rammasun," which ravaged the southern China and left more than 30 people dead.

However, the delays and cancellations are expected to continue in the following weeks, or at least 26 days as estimated by CCTV.

The restrictions will affect the operations of Shanghai Hongqiao, Shanghai Pudong, Nanjing, Hangzhou, Hefei, Jinan, Wuxi, Ningbo, Qingdao, Lianyungang, Zhengzhou and Wuhan airports until August 15, CCTV said, citing the "high-frequency exercises conducted by another party." No further details discussed.

While the reason behind the air traffic restriction remains unclear, its effect to the airport operation was sure.

Hongqiao airport's punctuality rate fell to about 40 percent on Monday, while Pudong airport delivered 26 percent efficiency in its operation for outbound flights, according to Shanghai Daily.

The reported delays add to China's image as a country with worst flight delays in the world.

The Capital International Airport, the largest airport in China, has the most delayed flights according to air travel information service FlightStats, with only 18.3 percent of its flights flew as scheduled. Over 40 percent of flights were delayed by at least 45 minutes, it added.

Next to the list is the Hongqiao airport, with 24 percent efficiency delivering passengers on time based on a report released in 2013.

TagsHongqiao International Airport, Pudong International Airport, Shanghai flights