Tasnim | Mohammad Hassanzadeh: The 6th International Exhibition of Rail Transportation was opened in Tehran on Tuesday. The international exhibition was inaugurated in the presence of Iranian Minister of Roads and Urban Development, Minister of Industry, Mine and Trade, Minister of Defense, vice President for science and technology and some other officials of the country. About 200 Iranian companies and 90 foreign companies attend the exhibition and it is expected a number of achievements in this field to be exploited.