article_snippet.sent: Officials are concerned about the behavior of the conquerors, particularly the Iranian-backed Shiite militiamen who helped Iraqi troops.
article_snippet.sent: Officials fear the militiamen might take "scorched earth" reprisals for the reported massacre of Shiite air force cadets by ISIS fighters in Tikrit last year.
article_snippet.sent: And officials fear that reprisals by Shiite militias against the population of Tikrit could stoke local anger, jeopardizing the government's ability to hold onto Tikrit and pull the government together.
article_snippet.sent: Sectarian resentment helped fuel the rise of ISIS in the first place. '
article_snippet.sent: demand families of soldiers captured by ISIS .
article_snippet.sent: But help from the coalition of Shiite militiamen and volunteers also played a part.
article_snippet.sent: The militia members, estimated to number around 20,000, are backed by Iran.
article_snippet.sent: The offensive marked the first open participation of Iranian advisers on the front lines in Iraq.
highlights_snippet.sent: Officials hope to avoid Shia reprisals for ISIS slaughter of air force recruits .