In Iraq, armed forces have launched an operation to capture the last Islamic State-held enclave in Mosul. In a statement, Iraqi military said, joint forces have begun liberating the remaining districts.<br/><br/>It said, the air force dropped leaflets urging residents in the enclave to flee. The enclave covers mainly the Old City center and three adjacent districts alongside the western bank of the Tigris river.<br/><br/>The U.S.-backed offensive on Mosul, now in its eighth month, has taken longer than planned as the militants have dug deap, and are fighting back fiercely. The fall of the city would effectively mark the end of Iraqi half of the caliphate declared nearly three years ago by Islamic State leader Abu Bakr al-Baghdadi, which also covers parts of Syria.<br/><br/>Meanwhile, United Nations has expressed deep concern for the thousands of civilians trapped behind Islamic State lines. In a statement today, UN's Under-Secretary General for humanitarian affairs Stephen O'Brien said, families are being shut inside booby-trapped homes and children being deliberately targeted by snipers.