Egyptian security forces killed seven suspected militants on Sunday during raids on hideouts in two villages in northern Sinai, security officials said.
Tensions in Sinai, the desert peninsula that borders Israel and the Gaza Strip, have escalated sharply over the past week after suspected militants killed 16 Egyptian soldiers near the border.
Sunday's deaths were the first reported casualties among suspected militants since Egypt launched a major offensive against the groups and sent reinforcements to the area following the attack last Sunday.
Security officials said the raids by troops and police backed by armoured vehicles targeted the villages near El-Arish of al-Ghora and al-Mahdiyah. They seized landmines, an anti-aircraft missile, heavy machine-guns and grenades. They spoke on condition of anonymity because they were not authorized to speak to the media.
They said the seven suspected militants were killed when the forces shelled a house in which they took cover after an exchange of fire. The shelling set the house on fire along with a car and a motorbike parked outside.
In a separate incident, three policemen were killed and four others injured when their car turned over while chasing a group of criminals in central Sinai, Egypt's official Middle East News Agency, MENA, reported.
It also said that suspected militants fired at a security checkpoint before escaping in northern Sinai on Saturday. No casualties were reported.
Large swathes of northern Sinai have plunged into lawlessness following Hosni Mubarak's ouster in the uprising last year, with a massive flow of arms smuggled from Libya finding their way into the hands of disgruntled Bedouins.
The lawlessness is coupled with the rise there of al-Qaeda-inspired militant groups waging a campaign of violence against Egyptian security forces. They have also staged several cross-border attacks on Israel.
Some of Sinai's native Bedouins are resentful of what they see as the police's heavy-handedness and neglect by the central government in Cairo.
Recent years saw some Bedouins trafficking in black African migrants seeking a better life in neighbouring Israel, growing illicit drugs and supplying Gaza's merchants with goods that are smuggled through a network of underground tunnels.