The so-called Islamic State (IS) group said it was behind the attack.
The incident came hours after three foreign tourists were stabbed by suspected IS militants who stormed a hotel in the Red Sea resort of Hurghada.
Egypt is battling an insurgency largely based in the Sinai Peninsula which became more active after the overthrow of Islamist President Mohammed Morsi.
Hundreds of security force members and government personnel have been killed, with attacks creeping closer to the capital Cairo.
The instability has threatened Egypt’s important tourism industry.tweet Follow @@metrolens1