DUBAI - Iranian authorities have arrested hundreds of people and executed half a dozen in a sweeping security crackdown that analysts say is aimed at exerting control after a brief but punishing war with Israel exposed Iran’s deep infiltration by Israeli intelligence.

Iran said that more than 900 people were killed in its nearly two-week war with Israel, which subsided with a ceasefire shortly after the U.S. carried out strikes on three of Iran’s underground nuclear facilities.