Bulgarian authorities announced Friday that two military pilots were killed in a training plane crash in the south of the country.Bulgarian Defense Minister Atanas Zapriyanov said that the crash of the military training plane resulted in the death of the pilots, and the aircraft was an "L-39ZA" crashed near the Graf Ignatiyevo air base in the south of the country.The plane crash comes a day before a scheduled military air show. The Bulgarian authorities announced opening an investigation to determine the cause of the accident.It is worth noting that in 2018, two Bulgarian soldiers were killed and a third was injured when a military helicopter carrying them crashed in the south of the country, near the Krumovo military base and Plovdiv civilian airport.Source: Qatar News Agency