The train was heading from Cairo to the Nile Delta city of Mansoura when four carriages derailed at 1.54pm, about 40km north of the capital, Egyptian National Railways said.
Authorities had initially said that 11 people were killed and 98 injured.
The public prosecutor yesterday ordered the detention of 23 people, including the train driver and other railway workers and officials, the statement said.
The cause of the accident is unclear and prosecutors are investigating whether there was negligence involved.
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