An Egyptian policeman and seven suspected activists were killed in a gunfight Tuesday, the interior ministry said on Tuesday.
He said three other police officers were also injured.
The exchange took place in the al-Amiyira district, the prosecutor said in a statement.
The ministry was informed “that there is a terrorist cell, the elements of which embrace the ideology of Takfiri, using several areas as a shelter in the east and south of Cairo as a starting point for carrying out terrorist operations”, indicates the press release.
Egypt uses the term takfiri to refer to Islamist activists who often accuse their victims of being infidels.
Two private TV stations broadcast what they called footage of the shooting, which Reuters was unable to verify immediately, and asked residents to stay inside.
Weapons and ammunition were found with the suspects, the ministry said.
The prosecutor said that a team of investigators had been sent to the scene of the attack.
Egypt has been fighting an Islamist insurgency in the northern part of the Sinai Peninsula since the ouster of Mohamed Morsi from the Muslim Brotherhood in 2013 following mass protests against his government.
The military and police launched a major campaign against militant groups in 2018, focusing on the Sinai Peninsula as well as the southern regions and the border with Libya.
The last major attack took place in November 2017, when activists killed more than 300 people in an attack on a mosque in northern Sinai, the deadliest incident in the most populous country in the Arab world.