Some 30,000 civilians are trapped by fighting in Tal Afar, according to the United Nations, a city Iraqi forces are working to take back from the Daesh terrorist group. "Humanitarian assistance is being provided at assembly points to the south and east of Tal Afar town, with more than 300 people having passed through these points yesterday and receiving assistance," U.N. Secretary General Antonio Guterres's spokesman Stephane Dujarric told journalists on Tuesday.

The U.N.'s refugee agency (UNHCR) fears Iraqi civilians "are likely to be used as human shields" and that "attempts to flee could result in executions and shootings," according to Dujarric. UNHCR "calls on all parties to the conflict to allow civilians to leave the conflict area and to allow access to safety," he said.

The U.N. said Monday it expected thousands of civilians to flee the area in the days and weeks to come. Iraqi forces recaptured from Daesh the first three districts of terrorist bastion Tal Afar as the Pentagon chief visited Baghdad in a show of support. After meeting Iraqi Prime Minister Haider al-Abadi in Baghdad, U.S. Defense Secretary Jim Mattis said the militants were "on the run." "Cities have been liberated, people freed from Daesh," Mattis said.