More than one million Iraqis have been forced from their homes to date this year amid fighting between armed militias and government forces, the United Nations has said.
UN officials said on Tuesday that the exodus could only be expected to increase as the conflicts continue.
Jens Laerke, spokesman for the UN Humanitarian Affairs Agency, told a press conference at the UN office in Geneva on Tuesday that 650,000 people had fled their homes in June alone.
Iraq saw a marked increase in sectarian violence between Sunni and Shia Muslims in June, with a coalition of armed opposition groups led by the Islamic State of Iraq and the Levant having taking control of large swathes of the country's predominantly Sunni provinces.
The latest wave of insurgency began when militants captured the city of Mosul on 10 June and soon afterwards took control of a number of other key cities and towns including Tikrit, Tal Afar, Fallujah and Baiji.
Meanwhile, nine civilians were killed during an Iraqi army offensive in the city of Fallujah, hospital sources said.
Wisam al-Isawi from the Falluja State Hospital told the Anadolu Agency that Iraqi air forces had launched air strikes on different parts of the city.
He added that 15 others were injured during the offensive and some were in critical condition.
