The UN refugee agency says some 900 people have fled the Iraqi city of Mosul and crossed the border into Syria. <br/><br/>This has been informed by a spokeswoman for the Office of UN High Commissioner for Refugees (UNHCR).<br/> <br/>This is the first large group of civilians confirmed to have escaped since the Iraqi government began its offensive to liberate Mosul from the so-called Islamic State (IS) on Monday. <br/> <br/>There are fears the militants will use the civilians as human shields as Iraqi forces get closer to Mosul. <br/> <br/>US President Barack Obama said yesterday it was important to ensure that Mosul's residents could safely flee the city.<br/> <br/>The UN is working to create new refugee camps to the south, east and north of Mosul, and predict some 200,000 people will need shelter in the first days and weeks of the operation. <br/><br/>But many of those who have already escaped have moved west to camps across the border in Syria, including Al Hol camp.