UN says Mosul displacement gathering pace as Iraq battles IS

The United Nations says around 45,000 people have fled the fighting between Iraqi forces and Islamic State militants in western Mosul over the past week, a 22 percent increase from the previous week.

The U.N. humanitarian aid office said Wednesday that the latest wave brought the total number of people displaced from western Mosul to about 135,000. OCHA says camp construction and site expansion "are accelerating to meet needs."

U.S.-backed Iraqi forces launched an operation on Feb. 19 to drive IS from the western half of Iraq's second largest city after declaring eastern Mosul "fully liberated" the previous month.

OCHA says about 330,000 people have been displaced since the Mosul operation began in October. Of those, only 72,000 have returned.