Egyptian security forces say a roadside bomb planted by militants in the Sinai Peninsula has injured at least nine police cadets.

The remote-controlled bomb went off on the outskirts of the coastal city of el-Arish in northern Sinai near a bus full of police conscripts, said a security official, who spoke on condition of anonymity, on Monday.

The bus was traveling from the town of Rafah, near the Gaza border, to the coastal city escorted by an armored police car.

The attack is a reminder of the August 19 ambush when militants pulled 25 police conscripts off a minibus in the same region and shot them dead on the side of the road.

The Sinai has long been considered a safe haven for militants who use the region as a base for terror activities. In recent months, the remote desert region has been the scene of growing violence and militant attacks on security forces.

Since the ouster of former Egyptian president, Mohamed Morsi, on July 3, militant groups have launched almost daily attacks in Sinai, killing members of the security forces. In response, Cairo has launched offensives against the militants, sending thousands of troops backed by tanks and heavy equipment into the region.

On Sunday, the Egyptian army said it will press ahead with its campaign in the Sinai Peninsula, keeping the Gaza Strip closed to the outside world, as the Rafah border crossing to the coastal enclave is still shut.