On Thursday, Egypt’s Interior Ministry said the militants were members of a group accused of being behind an attack earlier in the week.
A car packed with explosives detonated outside Egypt’s main cancer hospital in Cairo, killing at least 20 people.
The group, known as Hasm, has links to the outlawed Muslim Brotherhood.
The ministry says at least eight militants were killed when they opened fire at police forces storming their hideout in the town of Atsa in Fayoum.
Another seven militants were killed in a firefight with police in Cairo’s Shorouk suburb.