cairo egyptian president abdel fattah al-sisi appoint new arm force chief staff saturday interior ministry dismiss several high-ranking officials apparent reorganization country security command reason give reshuffle interior ministry decision come week deadly attack police operation western desert area giza province ministry say 16 police kill come heavy fire egyptian force fight several arm islamist group mostly northern part sinai peninsula since sisi help lead military overthrow president mohamed mursi muslim brotherhood 2013. hundreds members security force kill attack militants recent years local islamic state affiliate main foe security force north sinai statement presidency say gen. mohamed farid hegazy would replace gen. mahmoud hegazy make president adviser strategic plan crisis management separate statement interior ministry announce replace several high-ranking officials include head homeland security assistant minister security giza province director giza security director operations central security give detail shakeup militant group yet claim responsibility last week attack police remote desert area giza 130 km 80 miles southwest capital cairo thirteen militants kill raid farm hideout region friday state news agency mena quote security official say revenge blood men martyr last week oasis vast western desert region always security headache arm flow across frontier libya militant group find shelter since country fell chaos 2011 end muammar gaddafi rule sisi former military commander elect landslide 2014 present bulwark islamist militancy widely expect run re-election next year egypt announce reshuffle top security rank