Eight Central Security Forces (CSF) conscripts were injured Monday when their bus came under attack west of Al-Arish city in north Sinai, Egypt's state news agency MENA reported. One civilian was also injured and all nine were transferred to the hospital.

Circumstances of the attack remain unclear, however, MENA reported that the bus was hit by a roadside bomb while a security source told Al-Ahram Arabic news webiste that the bus, which was guarded by two armoured vehicles, was targeted by an RPG rocket in the Al-Reesa region, leaving seven -- not eight -- conscripts injured.

Apache helicopters were deployed to locate the assailants after they were chased by security forces, according to Al-Ahram.

Conscripts in the city of Al-Arish gathered to protest the attack against their colleagues, calling on the Interior Ministry to visit the city and witness their difficult living and working conditions.

Since Islamist president Mohamed Morsi's 3 July ouster by the military amid mass protests against his one-year rule, Islamist militant groups stepped up their attacks against security forces in the northern Sinai Peninsula. The Egyptian Armed Forces responded by launching a large-scale operation to eradicate their activity in the restive area.