Security and medical officials say a roadside bomb has killed a police officer and wounded three conscripts in Egypt's northern Sinai city of el-Arish.
The officials say Friday's blast targeted an armored car carrying the four as they traveled to a security checkpoint.
No group immediately claimed responsibility for the attack.
An Islamic State affiliate based in northern Sinai and other militant groups have carried out dozens of attacks, mainly targeting security forces, since the military overthrow of Islamist President Mohammed Morsi in 2013.
The officials spoke on condition of anonymity because they are not authorized to brief reporters. The northern part of the Sinai Peninsula is mostly off limits to media.