Egyptian security forces have raided a village near the Giza Pyramids outside Cairo, hunting for suspects in the killing of 15 policemen last month.
It was the latest move by authorities to assert state control over anti-government strongholds that have resisted state authority since a July 3 coup toppled President Mohamed Morsi.
Security forces backed by armoured vehicles and accompanied by masked commandos conducted house-to-house raids in the village of Nahya early on Tuesday morning, searching for suspects of the August 14 attack on policemen in the adjacent town of Kerdasa.
That attack is assumed to be in retaliation for a violent assault that day by security forces on pro-Morsi protest camps in Cairo that left hundreds dead and sparked days of unrest.
Police stayed out of Kerdasa for over a month after the killings, and residents say Morsi supporters dominated the town.
The military and police went back in last week, sparking a gun battle in which a senior police officer was shot dead and the arrests of scores of suspects.
The scenes were reminiscent of the Egyptian government's battle with what it labelled an "Islamist insurgency" in the 1990s, a battle which lasted years and left thousands dead.
Anti-government violence continued on Tuesday, meanwhile, as the AFP news agency reported that armed men killed an Egyptian policeman in an attack on his vehicle near the Suez Canal city of Ismailiya, security officials said.
Two officers were also wounded in the attack.
More than 100 policemen have been killed across Egypt in attacks and clashes since the military coup.
Morsi's supporters have held mostly peaceful protests, but hundreds of them have been killed by state security forces.