At least nine Islamist militants have been killed in a major offensive by the Egyptian army in Sinai, security officials have said.
Eyewitnesses told the BBC that tanks and troops, backed by Apache helicopters, had struck the militants in towns along the Gaza Strip border.
The operation is said to be the biggest of its kind in recent years in Sinai.
Meanwhile, Egyptian soldiers defused mortars and other explosives found on a railway line near the Suez Canal.
There have been frequent attacks on pipelines and security forces since the uprising that toppled former President Hosni Mubarak in 2011.
On Thursday a powerful explosion targeted Interior Minister Mohamed Ibrahim as he left his Cairo house for work. He survived unscathed, but officials say another person died.
And on 24 August, at least 24 Egyptian policemen were killed in a militant ambush in the Sinai peninsula.
Column of tanks
The Sinai military offensive targeted suspected militant outposts near the towns of Rafah and Sheikh Zuweyid, as well as nearby villages, reports say.
Army helicopters carried out air strikes aimed at destroying weapons caches, vehicles and hideouts.
A military official, who spoke anonymously, told the Associated Press that the army would “clean” the areas in Sinai where Islamic militants operated.
A witness told the news agency he had seen a column of tanks, trucks carrying infantry, rocket launchers and other military vehicles. Smoke was also seen rising from the area.
A security official said “dozens” of insurgent suspects had been wounded in the attack.
“This is by far the largest operation we have seen and the one we have been waiting for,” said Sheikh Hassan Khalaf, a tribal leader from the targeted area.
The northern Sinai has long been a haven for militant groups, but clashes with the army have surged since July when Mr Morsi was deposed, the BBC’s Bethany Bell, in Cairo, reports.
The army has accused the ousted leader of being too lenient toward militant activity in the region, after he released Islamists from prison and vetoed military operations in Sinai.
Rebel fighters in the region can threaten Israeli cities with long-range rockets. Weapons are being trafficked across the desert from Sudan and Libya into the Hamas-run Gaza.
Analysts say the army’s crackdown down on Mr Morsi and his Muslim Brotherhood is adding impetus to militants in the northern desert.
Egyptian deployments in the peninsula are subject to the 1979 peace treaty between Israel and Egypt.