Up to 10 Egyptian soldiers were killed and three wounded on Thursday when a bomb hit an armoured vehicle south of Bir Al Abd city in the northern Sinai region, officials said.
The officials said the dead included an officer.
Military spokesman Tamer Refai confirmed the attack but did not specify the number of soldiers killed and wounded by the improvised explosive device.
President Abdel Fattah El Sisi sent his condolences in a Facebook post, praising the fallen soldiers as heroes and martyrs.
The attack was not immediately claimed by any group, but militants loyal to ISIS are active in the strategic border region.
Egypt has been fighting extremist insurgents who have killed hundreds of police and soldiers in the northern part of the Sinai Peninsula since the removal of president Mohammed Morsi in 2013 after mass protests against his rule.
Militants have also carried out attacks elsewhere in the country.
An Egyptian policeman and seven militants were killed on April 14 in a gunfight after the interior ministry was tipped off about possible Easter attacks against Coptic Christians, the ministry said.
It said three policemen were wounded.
In February 2018, Egyptian security forces launched a nationwide, large-scale operation against militants, mainly focused on the northern Sinai region and the border with Libya.
More than 845 militants have been killed in the region, along with more than 60 security personnel, army figures show.