Two police officers were killed and four wounded after an IED exploded near a security convoy in North Sinai's capital city of Arish on Thursday.   A statement by Egypt's interior ministry identified the victims as a lieutenant colonel and a captain.   The attack comes one day after a police colonel was killed in a bomb attack on a security checkpoint in the same city.   Egypt’s army and police forces have been waging a war over the past several years against an Islamist militant insurgency in North Sinai, concentrated in the cities of Arish, Rafah and Sheikh Zweid.   Hundreds of security personnel have been killed in terror attacks by militants.   The army says it has killed hundreds of militants in intensified comprehensive military campaigns in the governorate since 2013 Source: Ahram online