The United Nations and Save the Children were in Iraqi Kurdistan Sunday where an estimated 17,000 Syrians have arrived in the past few days, most crossing the Tigris River on a new pontoon bridge.
"This is an unprecedented influx of refugees," Alan Paul, team leader for Save the Children, told the BBC. "The main concern is that so many of them are stuck out in the open at the border or in emergency reception areas with limited, if any, access to basic services."
The U.N. High Commissioner for Refugees said the refugee surge was one of the biggest exoduses from Syria since the rebellion broke out in 2011. Officials suspect increasing clashes between Syrian Kurds and Islamist militants was behind the increase.
Kurds make up about 10 percent of Syria's population, but the U.N. said it had not compiled statistics on the ethnicity of the refugees entering Iraqi Kurdistan.
The United Nations also said a team of its chemical weapons inspectors had arrived in Syria to look into claims toxic gas had been used on the battle field. The much-delayed, two-week mission will include visits to three sites, including the northern Syrian town of Khan al-Assal, which the BBC said was the center of the allegations the government deployed chemical weapons against civilians.