Gunmen opened fire on a checkpoint in Cairo Saturday, killing five Egyptian soldiers, state television reported.
The attack comes two days after gunmen attacked a military bus in the capital, killing a soldier. Militants have launched scores of attacks, mainly targeting security forces, since the military overthrew Islamist president Mohamed Morsi in July.
Most of the attacks have taken place in the restive Sinai Peninsula, but in recent months militants have expanded their reach to the Nile Delta and the capital.
The government has blamed much of the violence on Morsi's Muslim Brotherhood, which renounced violence decades ago and has denied any involvement.
The most prominent attacks, including a car bombing at a police headquarters in Cairo and the downing of a military helicopter in Sinai, have been claimed by Ansar Beit al-Maqdis (Partisans of Jerusalem), a Sinai-based jihadist movement.
The group has said the attacks are in retaliation for a brutal government crackdown on Morsi's Islamist supporters, which Amnesty International says has claimed some 1,400 lives.
Morsi was elected in Egypt's first-ever democratic presidential election, following the 2011 uprising that toppled long-ruling dictator Hosni Mubarak.
But his year in power bitterly polarised Egyptians, and last summer the military ousted him amid massive street protests demanding his overthrow.