Egypt's interim government has pledged "decisive" action and ordered heightened security after gunmen killed six soldiers at a Cairo checkpoint.
Masked gunmen opened fire on military policemen as they were finishing their morning Muslim prayers and then planted two bombs to target first responders.
In an emergency meeting on Sunday, the cabinet emphasised that attacks on the army would be dealt with by military courts, in accordance with a constitution approved in a referendum in January.
The government also ordered heightened security measures to counter what has become a low-level insurgency that has killed more than 200 soldiers and policemen since the overthrow of Islamist president Mohamed Morsi last July.
The government has mostly blamed Morsi's Muslim Brotherhood, which renounced violence decades ago and has denied any involvement.
Egypt is preparing for a presidential election that will likely be contested and won by army chief Abdel Fattah al-Sisi, the field marshal who overthrew Mr Morsi.