Resigned minister of transportation Rashad El-Metiny was released without bail following his second session of questioning over Saturday's fatal accident in Assiut.
Investigations of El-Metiny and Mostafa Qenawy ex-head of the Railway Authority, that started on Saturday following the tragic Assiut train-bus accident, continued on Sunday.
On Saturday, Egypt's public prosecutor barred El-Metiny from travelling until investigations are over.
Meanwhile, the crossing guard who was on duty at the time of the accident remains in detention for 15 days pending investigations.
On Saturday, a train crashed into a kindergarten school bus in Al-Manfalout village in Upper Egypt's Assiut governorate, causing the death of 51, the vast majority children aged four to six.
Following the accident, both the minister of transportation and the Railway Authority head submitted their resignations.