A China Southern Airlines pilot stabbed two colleagues before jumping to his death Monday morning at the airline's Jilin branch office in northeast China's Changchun city, police said in a statement on July 2.

The incident occurred around 10:22am on July 1 when the 31-year-old pilot, surnamed Li, reportedly upset over failing a competency evaluation, attacked his supervisors during a meeting.

Li then broke a 15th-floor window and jumped to his death, Xiaoxiang Morning Post reported.

The victims sustained non-life-threatening injuries.

China Southern Airlines' Jilin branch declined to comment when contacted by multiple media outlets.

Police said the case is under further investigation.