Iran has made a significant number of arrests following a major security breach that led to the assassination of a senior Hamas leader in Tehran. The arrests include senior intelligence officers, military officials, and staff members at a military-operated guesthouse where the assassination took place. The assassination of Ismail Haniyeh, who was visiting Tehran for the inauguration of Iran's new president, has prompted a strong response from Iranian authorities, indicating a serious failure in security. The investigation is being led by the Revolutionary Guards Corps' specialized intelligence unit, and Iran has vowed severe revenge, with the supreme leader ordering a strike on Israel in retaliation. The intensity of the investigation reflects the shock and concern within Iran's leadership over the security breach. The article also highlights the ongoing covert war between Iran and Israel, with both countries engaging in various acts of sabotage and assassination. The Iranian government has implemented extensive security measures, including overhauling security protocols for senior officials and conducting thorough investigations at airports in an effort to apprehend the perpetrators. The former president of Iran has called for cooperation among security, intelligence, and military branches to address the threat posed by the assassination.