North Korea launched more trash-filled balloons towards South Korea on Tuesday night, for a second consecutive night, disrupting flights at Incheon International Airport. 

According to the Incheon International Airport Corporation, takeoffs and arrivals of domestic and international flights were suspended or delayed for about three hours from 1:46 a.m. to 4:44 a.m. Wednesday.

The corporation said that it suspended or delayed flights due to the risk of an accident involving the balloons possibly being sucked into airplane engines. 

Flights resumed normal operations as of 7 a.m.

South Korea’s Joint Chiefs of Staff said North Korea flew trash-carrying balloons again on Tuesday night after launching some 350 balloons the previous night. 

The latest batch of balloons marks the sixth launch since late May.