The Air Force has grounded some 160 fighter jets whose engines are the same model as a KF-16 fighter jet that suffered an accident during an air drill in the U.S. state of Alaska on Wednesday.

According to South Korea’s Air Force on Thursday, the planes that have been grounded include some 30 imported F-16s, around 130 domestically manufactured KF-16s and a few F-15Ks. 

The military plans to have the planes grounded until the cause of Wednesday’s accident is confirmed. 

Two South Korean pilots escaped a burning KF-16 fighter jet during takeoff at the Eielson Air Base around 9 a.m. Korea Standard Time Wednesday. 

The pilots were taking part in the Red Flag Alaska drills.

The Air Force said an investigation team and emergency maintenance team personnel that it sent to Eielson Air Base began work shortly upon arrival earlier in the day.