At least four Egyptian soldiers have been wounded in a bomb explosion in the troubled Sinai Peninsula, security sources say.

According to the sources, who spoke on condition of anonymity, the explosion took place on Wednesday near the Rafah border crossing with the Gaza Strip.

The injured were transferred to a military hospital in the coastal city of el-Arish in northern Sinai, the sources added.

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 September 16, a roadside bomb planted by militants in the peninsula injured at least nine police cadets.

According to security sources, the remote-controlled bomb exploded on the outskirts of el-Arish near a bus full of police conscripts.

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.