Egypt's army has vowed to press ahead with its "war" against Islamist militancy in Egypt's Sinai Peninsula, hours after a deadly blast killed 10 soldiers in the restive region which borders Israel.

Ten soldiers were killed and 35 wounded as a car bomb targeted a military convoy Wednesday morning west of the North Sinai town of Sheikh Zuwaid.

"The armed forces assert they will carry on the war against black terrorism...purge Egypt and secure its people from treacherous violence," Egypt's army spokesman, Colonel Ahmed quellAli said.

The attack took place at 7:45am, as soldiers were travelling to begin their vacation, Ali added.

Wednesday's bombing was the bloodiest since mid-August, when gunmen killed 25 policemen in an ambush on a security convoy in Rafah.

Egypt's army has waged a broad offensive in the restive peninsula to flush out the mounting militancy which killed dozens of soldiers and policemen in near daily attacks since the July ouster of Islamist president Mohamed Morsi.

Dozens of Islamist insurgents were killed in military air and ground offensives targeting hideouts and arms depots over the past two months.

Egypt's security forces have also launched a fierce crackdown on pro-Morsi Islamists elsewhere in the country, with hundreds killed in street violence and thousands arrested nationwide.

A Sinai-based militant group, Ansar Bayt Al-Maqdis, claimed responsibility in a Tuesday statement for the killing of a high-ranking security officer in Cairo on Sunday.

The same group was behind a failed assassination attempt on Egypt's interior minister in September, and nearly a dozen bombings of a gas pipeline connecting Egypt, Israel and Jordan.

Attacks in the capital have fuelled fears that militant insurgency might metastasise across other parts of the country.