They are hopped up on goofballs. Specifically, Tramadol. An opioid analgesic that allows the Islamic Rage-Boys to take a beating and not even feel it.
Drug popping adversaries are the thing that always makes the army get rid of .38s in favor of .45s (see: Mindanao 100 years ago). So, if Egypt turns nasty, they should remember the old lessons and leave the Berettas on the ship.
"Zombies operating under the control of Islamists and Leftists — working together. Who said they couldn’t get along? "
And remember, headshots for zombies that feel no pain.