A policeman was killed and three others were wounded on Saturday when armed attackers shot at a police van on the Cairo-Fayoum road.
The Fayoum security department said the van was carrying prisoners, none of whom fled during the attack.
Militant elements have killed at least 700 army and police officers since the 2013 uprising that toppled former president Mohamed Morsi.
Edited translation from Al-Masry Al-Youm