A police captain was killed and another injured Sunday at dawn when an improvised explosive device (IED) detonated as their police vehicle traveled through North Sinai's Al-Hassna highway, Egypt's interior ministry said in an official statement.
The interior ministry said security forces were intensifying efforts to catch the culprits.
No group has yet claimed responsibility for the attack.
An Islamist insurgency has spiked in North Sinai following the ouster of president Mohamed Morsi in 2013, with militants targeting police and army personnel.
Sunday's attack comes amid an intensified third phase of Egypt's comprehensive military campaign to purge the restive governorate of militants through "pre-emptive strikes against terrorist elements."
Over 100 militants have been killed so far since the third phase was launched end of May.