As a pending deadline fast approaches relating to the return of overseas North Korean workers, DPRK state airline Air Koryo has significantly expanded its Pyongyang-Vladivostok service for December.

In a development first reported by South Korea’s Yonhap News Agency, data analyzed from the NK Pro Aviation Tracker and Vladivostok International Airport schedule together showed a total of 28 round-trip flights will be flown between the two cities in December.

Air Koryo’s official schedule shows it would normally fly to Vladivostok just twice a week – on Mondays and Fridays – meaning the airline is putting on