Funerals were held in several provinces for those killed, whose coffins were wrapped in Egyptian flags.
Al-Arabiya correspondent in Cairo reported on Friday that 16 security forces personnel were killed in clashes with militants in Giza, southwest Cairo.
The UN Security Council on Saturday condemned "in the strongest terms" Friday's terrorist attack in El Wahat desert in Egypt, where a large number of policemen were killed and injured.
The Egyptian authorities have not released an official death toll yet.
Security sources said a convoy of police vehicles were following a lead to a suspected hideout of the Hasm extremist group when they were ambushed from higher ground by militants firing rocket-propelled grenades and detonating explosive devices.
There has not yet been a claim of responsibility. "Islamic State" (IS) militants based in the Sinai Peninsula have also increased attacks across the country recently.
The country has been in a heightened state of turmoil and violence since the military overthrew President Mohammed Morsi of the Muslim Brotherhood, the country's first democratically-elected president, in mid-2013 following mass protests against his rule.
Condemnations of the latest attack came in from the Middle East and Europe, with France - where Sisi is due to visit next week - pledging solidarity after the losses for Egypt's security force in "the fight against terrorism". The Muslim Brotherhood has denied any involvement in violent attacks against security forces.
Analysts say a section of the Brotherhood has encouraged armed assaults against the police.
No group made any claim or statement about Friday's operation not far from the capital.
Hasam has claimed multiple attacks since 2016 on police, officials and judges in Cairo.
Egypt has been under a state of emergency since bombings and suicide attacks targeting minority Coptic Christians killed scores earlier this year.