Transport Minister Plamen Petrov demanded 12 resignations of directorates` and agencies` directors with the Transport Ministry, sources from the ministry said, quoted by Standart Daily. The heads of Civil Air Administration and Air Traffic Management will be replaced in days, according to the sources. Zahari Alexiev, director of Civil Air Administration (CAA) directorate, confirmed that he had received a formal acknowledgement from the Chief Secretary of the Ministry. A months or so ago Minister of Transport and Communications Plamen Petrov demanded the resignation of the CAA head and threw him out of the office building with the help of the police. The motives were that there were omissions in flights` security. On the next day Zahari Alexiev, all of a sudden, returned to work. The Bulgarian Railways CEO said he had not received any formal acknowledgement for resignation demand.