baghdad around 400,000 children still displace fight mosul one year start military offensive recapture iraqi city islamic state save children say monday islamic state self-declared caliphate effectively collapse july u.s.-backed iraqi force re-took mosul group de facto capital iraq grueling nine-month battle fight mosul stop mean humanitarian need great anything children need help ever still displace return see leave home say london-based charity iraq country director ana locsin large part mosul reduce rubble school home hospitals roads playgrounds park speak dozens children haunt experience leave psychological scar take years heal locsin say statement fall mosul small towns country north west area still control islamic state iraq stretch alongside western border syria militant group also retreat 400,000 children still displace mosul fight save children