Egyptian police shot dead four suspected militants inside a house, a few miles from central Cairo, the Interior Ministry said on Sunday, the third such incident in as many weeks.
The ministry stated that the militants were making explosives in a rented house, south of Cairo. The ministry did not say whether anyone was arrested.
The militants belong to Ajnad Misr, a group that emerged in January 2014, which targets security forces in and around Cairo.
According to statements, the suspects had opened fire first, it said.
"Engagement resulted in the death of four known elements and the uncovering of an assault rifle, a 9mm pistol, an improvised firearm, a car previously used in many terrorist attacks, and a motorcycle without licence plates," a ministry statement said.
The men were suspects in the killing of two policemen, a soldier and a civilian, and they were also suspected of blowing up a police vehicle and bombing a security checkpoint, it said.
Egypt is fighting an insurgency in Sinai that gained momentum in mid-2013, when the military ousted President Mohamed Morsi.
Since then, Ajnad Misr has claimed responsibility for several attacks all over the country.
The Muslim Brotherhood considers the movement to be peaceful, however, Egyptian Security Forces do not differentiate between it and groups such as Ajnad Misr and DAESH.
DAESH-affiliated militants sometimes carry out attacks in Cairo and other cities, but are most active in Sinai, a strategic peninsula bordering Israel, Gaza and the Suez Canal.
Police killed two men, suspected of being members of Ajnad Misr, at a Cairo apartment on Wednesday.
They also killed four suspected militants in three raids on Jan. 25, the fifth anniversary of the 2011 uprising that was in part sparked by rampant police brutality, which ended the 30-year rule of autocrat Hosni Mubarak.
The Interior Ministry says raids only occur with a warrant from a prosecutor, and that police do not shoot unless they are shot at.