The militants fired mortar shells on the Karam el-Qawadis security checkpoint and fled from the scene, the officials at the Security Directorate of North Sinai said.
The injured was admitted to a hospital and security forces along with military planes were combing the area to locate the attackers, they said.
North Sinai has witnessed several violent attacks by militants since the January 2011 revolution that toppled the ex-president Hosni Mubarak.
The attacks targeting police and military increased after the ouster of Islamist ex-president Mohamed Morsi in 2013. Hundreds of security personnels have been killed since then.