EDITORS PLEASE NOTE: THIS EDIT CONTAINS GRAPHIC CONTENT.
The collision happened after the emergency brakes on one of the trains, which were traveling in the same direction, were triggered by "unknown individuals," the rail authority said.
The brakes caused one of the trains to stop and the second to crash into it from behind, it said. The authority is conducting further investigations, it added.
The public prosecutor's office said it had ordered an investigation into the crash close to the Nile-side town of Tahta, about 365 km (230 miles) south of Cairo.
Egypt has one of the oldest and largest rail networks in the region and accidents involving casualties are common.
- [SPEAKING ARABIC]
INTERPRETER: We need an official to come and see what's happened. They can't remove the people from under the trains. It's terrible! Look at the children! We need a crane but it's in Asyut. People are dead! We can't even save the ones who are alive.
[YELLING IN ARABIC]