The Egyptian army has been pounding Islamist positions in north and central Sinai regions after the Islamic State (Isis) group launched an attack killing 12 soldiers. In what is likely to be a lengthy anti-terror aerial campaign against the insurgents, the army said the air strikes are to continue in the coming days.

The army said "terrorist elements" in several areas have been eliminated during the targeted air strikes. The Egyptian aerial bombardment that started on Saturday (15 October) to "avenge the blood" of slain soldiers is thought to be continuing since then. The initial air strike lasted for about three hours taking down militants' positions, weapons storage facilities and several vehicles.

On Friday, the extremists carried out an attack in the restive Sinai peninsula, a thinly populated region, targeting a military checkpoint. The organisation quickly claimed responsibility for the onslaught while Egyptian forces said 15 of the assailants were killed in the attack.

So far, Egyptian air strikes have killed an unknown number of militants but some reports suggest the number could be more than 100.

An army spokesperson on Sunday (16 October) said security forces comprising special units and counter-terrorism teams of the army would aim to "capture and target terrorist elements and outlaws in the vicinity of villages, cities, and residential areas in North and Central Sinai".

He added that the Egyptian military would "adhere to the rules of engagement to ensure the safety of civilians who may be used as human shield by militants".

This is the first time the central Sinai area has come under attack although North Sinai has witnessed several onslaughts in the past. In September 2015, the Egyptian forces — after Abdel Fattah al-Sisi took over by overthrowing Muslim Brotherhood's Mohamed Morsi — mounted a similar air campaign billing it Operation Martyr's Right to root out militants.

The locally entrenched Islamic insurgency in Sinai quickly gained momentum due to the political chaos in Cairo and became pronounced when the militants pledged allegiance to the IS in 2014.