Crowds gather at a military checkpoint near Cairo where six army officers are dead.
State media reports that unidentified gunmen carried out the attack, which is the second on Egyptian security forces in three days.
A senior security official also told state TV that two bombs found nearby had been defused.
The army is blaming the outlawed Muslim Brotherhood movement, whose leaders have denied any involvement in the attack.
An Islamist insurgency targeting security forces has rocked Egypt since the military overthrew former President Mohamed Mursi last year.
