A growing number of flights between China and Japan have been canceled, with some routes seeing more than half of scheduled services scrapped, according to data from flight monitoring service DAST.

As of 10 a.m. on Monday, 12 China-Japan routes had canceled all flights. DAST monitoring indicates that the cancellation rate for flights to Japan is expected to peak at 21.6% on Dec. 27, the highest level in a month.

The hardest-hit routes include Tianjin Binhai to Kansai International Airport, with a 65% cancellation rate, followed by Nanjing Lukou to Kansai International at 59.4%, Guangzhou Baiyun to Kansai International at 31.3%, and Shanghai Pudong to Kansai International at 30.1%.