Ansar Beit al-Maqdis, an extremist group, allegedly connected with the Islamic State, has claimed responsibility for a number of similar attacks against police and soldiers, mainly in the northern Sinai province.
The reinforcement s deployed in the capital and around hotels and churches.
Egyptian security forces have faced insurgency from militant Islamists in the Sinai Peninsula since the 2011 uprising which forced President Hosni Mubarak from power after a 30-year rule. After his successor, Mohammed Morsi of the Muslim Brotherhood was ousted in 2013, the attacks increased in intensity, mostly targeting Egyptian government security forces.
Following months of confrontation between Islamist protesters and government forces, Egypt's ex-defense minister, Abdel Fattah Sisi, was elected as the new Egyptian president in May. Pro-Islamist protests in the country, however, continue.