Thousands of refugees from Syria are pouring over the border into Iraqi Kurdistan, the UN refugee agency says, BBC reported.
Up to 10,000 crossed at Peshkhabour on Saturday, adding to an earlier influx of 7,000 on Thursday.
The UN agencies, the Kurdish regional government and NGOs are struggling to cope, correspondents say.
The UN says the reasons are not fully clear, but there has been a sharp rise in clashes between Syrian Kurds and anti-government Islamist militants.
The UN High Commissioner for Refugees (UNHCR) says this is one of the biggest single waves of refugees it has had to deal with since the uprising against the rule of Syrian President Bashar al-Assad began in March 2011.