A colonel in the Egyptian military was killed and three recruits injured on Sunday when their armoured vehicle was hit by an explosion in the Sinai peninsula, security sources said.
The attack in the northern Sinai was the latest in an area where security forces have been battling the local affiliate of Islamic State, which authorities say has killed hundreds of members of the security forces.
The militants have also extended their campaign to other parts of Egypt, most recently attacking churches in Cairo and other cities with the loss of dozens of lives.
In a further escalation of the conflict in Sinai, militants last week opened fire on members of a Sinai tribe, the Tarabeen, which has been armed by the army, and killed 12 of them, according to security and tribal sources.
Islamic State said on Sunday a member of the group drove a motorcycle packed with explosives into a gathering of the tribesmen and detonated it, killing 15 and damaging military equipment.
No immediate comment was available from the army.