Two Egyptian soldiers were killed when a roadside bomb struck their armoured vehicle in North Sinai even as a major air and ground offensive in which the military claimed to have killed 31 militants entered its second day.
The incident occurred in al-Taweel region in the restive Sinai peninsula where one of the largest military operations in years is currently underway.
The operation has largely targeted militants in North Sinai towns of Sheikh Zwayed and Rafah amid heavy fighting between the army and the supporters of ousted Islamist President Mohammed Morsi.
Apache helicopters hit targets in north Sinai near the Rafah border crossing with the Hamas-ruled Gaza Strip.
At least 10 militants were killed in the operations yesterday, while 20 others were wounded and 15 arrested.
Egyptian security officials said seven helicopters took part in an assault on buildings where gunmen were holed up.
Egypt's official news agency MENA reported that helicopters attacked weapons caches and militants' vehicles in seven villages, cutting off the insurgents' communications in Northern Sinai and preventing them from contacting each other.
The army continued to destroy smuggling tunnels to Gaza, with a security official saying more than 90 per cent of the tunnels had been blown up.
The tunnels have been a lifeline for the flow of food, clothes, building materials and fuel into the impoverished territory, which Israel has blockaded since 2006.
Sinai has suffered from a security vacuum since the ouster of long-time ruler Hosni Mubarak over two years ago, but militant attacks have increased since July after Morsi was ousted.
In August, 25 police conscripts were killed when militants ambushed a personnel carrier near Rafah.
Sinai has long defied the central authority with its Bedouin population complaining of poverty and persecution.
The surge in militant attacks there and elsewhere around the country has raised fears of a revival of the Islamist insurgency that gripped Egypt in the 1990s.
